PUNCHES  AND  DIES 


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PUNCHES  AND  DIES 


LAYOUT,    CONSTRUCTION   AND   USE 


BY 

FRANK  A.   STANLEY 

H 

CONSULTING    MECHANICAL   ENGINEER;    EDITORIAL    REPRESENTATIVE   AMERICAN    MACHINIST; 

FACTORY    MANAGER    MARCHANT    CALCULATING     MACHINE     COMPANY;     MEMBER    AMERICAN 

SOCIETY    MECHANICAL    ENGINEERS;    AMERICAN    INSTITUTE    MINING    ENGINEERS; 

FRANKLIN  INSTITUTE;  HAWAIIAN  ENGINEERING  ASSOCIATION;  ASSOCIATE 

MEMBER   AMERICAN    INSTITUTE    ELECTRICAL   ENGINEERS;    AUTHOR, 

"AMERICAN  MACHINISTS  HANDBOOK;  "  "  AMERICAN  MACHIN- 
ISTS GRINDING  BOOK;"   "ACCURATE  TOOL  WORK;  " 
"AUTOMATIC  SCREW  MACHINES;  "  "  MACHINE 
SHOP  PRIMER;"   "THE  HILL  KINK 
BOOKS;"  ETC.,  ETC. 


FIRST  EDITION 


McGRAW-HILL  BOOK  COMPANY,  INC. 

239  WEST  39TH  STREET.    NEW  YORK 


LONDON:  HILL  PUBLISHING  CO.,  LTD. 

6  &  8  BOUVERIE  ST.,  E.  C. 

1919 


VT73xr.fr 

S7 


Library 


COPYRIGHT,  1919,  BY  THE 
McGRAw-HiLL  BOOK  COMPANY,  INC. 


Stanbope 

H.GILSON  COMPANY 
BOSTON,  U.S.A. 


PREFACE 


This  book  has  been  written  with  the  object  of  placing  before  die-makers, 
tool-makers  and  tool  draftsmen,  certain  definite  information  not  hereto- 
fore available  as  a  whole,  although  some  of  the  material  here  published 
is  necessarily  of  a  fundamental  character  with  which  all  mechanics  must 
familiarize  themselves  in  their  progress  toward  a  reasonably  complete 
knowledge  of  the  subject  of  press  tools  and  their  construction. 

Practically  ninety  per  cent  of  the  material  in  these  pages  has  been 
gathered  and  prepared  expressly  for  this  volume  and  is  here  published 
for  the  first  time.  The  remainder  has  been  selected  from  current  articles 
originally  published  by  the  author  and  by  other  contributors  to  the  tech- 
nical press.  For  information  taken  from  the  latter  sources  full  credit  is 
given  under  the  list  of  references  at  the  back  of  the  volume. 

In  gathering  photographs,  drawings  and  data  for  the  preparation  of 
this  book  the  author  has  been  accorded  free  access  to  the  methods  and 
practice  of  many  of  the  leading  plants  of  America  where  he  has  received 
the  hearty  cooperation  and  assistance  of  numerous  shop  executives,  tool 
room  foremen,  press  room  foremen,  die-makers  and  others,  and  full  appre- 
ciation of  this  invaluable  aid  is  herewith  expressed.  In  this  connection 
especial  thanks  are  due  the  following  firms  and  individuals: 

Marchant  Calculating  Machine  Co.,  E.  W.  Bliss  Co.,  Smith  Premier 
Typewriter  Co.,  Noiseless  Typewriter  Co.,  Westinghouse  Electric  and 
Manufacturing  Co.,  Waltham  Machine  Works,  B.  C.  Ames  Co.,  Henry 
Disston  Sons  Co.,  Aluminum  Products  Co.,  American  Coin  Register  Co., 
Holt  Manufacturing  Co.,  Gilro  Machine  Co.,  A.  H.  Marchant,  W.  Nona- 
maker,  F.  B.  Shear,  A.  L.  Howes,  J.  A.  Ruffin,  W.  P.  Smith,  F.  E.  Ross, 
A.  B.  Swift,  H.  C.  Lockey. 

THE  AUTHOB. 


392628 


CONTENTS 

PAGE 

PREFACE  v 

CHAPTER  I.     PRESS  TOOLS  IN  GENERAL 1 

Extension  of  Press  Uses  —  General  Classes  of  Dies  —  How  Tools  may  be 
Classified  —  Varying  Arrangement  of  Tools  —  The  Sub  Press  Die — A 
Word  about  Sectional  Dies  —  Blanking  Die  Action  —  The  Cutting  Edges- 

—  Piercing  Tools  —  Notching  and  Comb  Dies  —  Shaving  Tools  —  Cutting 
Off   or    Parting    Dies  —  Trimming    Dies  —  Hollow    Cutting    Tools  —  The 
Drawing  Process  —  Action  of  Drawing  Tools  —  Reducing  Dies  —  Bulging 
Dies  —  Bending  and  Forming  Tools  —  Swaging  Dies,  Embossing  Dies,  Etc., 
Coining  Dies  —  Heading  Dies  —  Riveting  and  Staking  Dies  —  Extruding 
Dies. 

CHAPTER  II.     BLANKING  DIES 23 

Blanking  and  Other  Operations  —  Simple  Open  Dies  —  Stock  Stops  —  A 
Pillar  Die  —  Wheel  Die  Details  —  Materials  Used  —  Bases,  Heads  and  Pins 

—  Blanking  Die  Clearance  or  Relief  —  Advantages  of  Shaving  Dies  —  Shav- 
ing Dies  Especially  Serviceable  —  Table  of  Die  Clearances  or  Relief  —  The 
Life  of  a  Die  —  Another  Form  of  Die  —  Clearance  between  Punch  and  Die 

—  Table  of  Clearances  Between  Punch  and  Die  —  Pressures  Required  for 
Blanking  —  The  Effect  of  Sheared  Tools  —  Position  of  Blank  Opening  in 
the  Die  —  Relative  Positions  of  Blanks  —  Amount  of  Stock  Between  Blanks 

—  Gang  Tools  —  Two  blanking  Dies  for  Thin  Work  —  Combined  Pad  and 
Stripper  —  The    Inverted    Type    of    Die  —  Relative    Advantages  —  Large 
Blanking   Tools  —  Internal   Blanking  Tools  —  Large   Oval   Die  —  Another 
Elliptical  Die  —  Details  of  Punch  and  Guide  Pins  —  Sectional  Construction 

—  A  Die  in  Halves  —  Dies  with  Several  Sections. 

CHAPTER  III.     PIERCING  TOOLS  —  BLANKING  AND  PIERCING  DIES 57 

Punch  Dies  —  Life  of  Tools  —  A  Double  Punch  and  Die  —  Dies  for  Closer 
Work  —  Table  of  Pressures  for  Piercing  —  Simple  Piercing  Tools  for  Strip 
Metal  —  A  Perforating  Die  —  Internal  Clearances  in  Piercing  Dies  —  Multiple 
Tools  —  Bushed  Dies  —  Second  Operation  Piercing  Tools  —  Pilots. —  Pro- 
gressive Section  —  Tools  for  a  Toothed  Piece  —  A  Sheared  Die  —  Piercing  a 
Slot  —  A  Three  Stage  Set  of  Dies  —  Dies  with  Spring  Plate  or  Stripper  for 
the  Punches  —  A  Sectional  Slot  Piercing  Die  —  Side  Piercing  Tools  — 
Punches  and  Holders  —  Tools  for  Piercing  Oblique  Holes. 

CHAPTER  IV.     COMPOUND  DIES  FOR  BLANKING  AND  PIERCING 92 

Compound  Die  for  a  Brass  Disk  —  Operation  of  Knock  Out  —  Blanking 
Punch  Details  —  A  Contrast  in  Construction  —  Making  a  Thin  Steel  Ring 

—  Positive  Knock  Out  —  Small  Gear  Wheel  Job  —  Action  of  the  Tools  — 
Washer  and  Key  Slot  Dies  —  Larger  Compound  Tools  —  Stripper  and  Knock 
Out  —  A  Rectangular  Piece  of  Work  —  Electrical  Work  Dies  —  A  Stator 
Punching  Die  —  Limits  in  Variation  —  Special  Form  of  Knock  Out  Bushing 

vii 


viii  CONTENTS 

PAGE 

CHAPTER  V.     CUTTING  OFF  DIES  OR  PARTING  TOOLS 112 

Piercing  and  Cutting  Off  Arrangement  —  End  Forming  Parting  Tools  —  A 
Slotting  and  Cutting  Off  Job  —  Parting  Tools  for  German  Silver  —  Piercing, 
Forming  and  Cutting  Off. 

CHAPTER  VI.     SHAVING  DIES  AND  THEIR  APPLICATIONS 121 

Uses  on  Heavy  Stock  —  Shaving  Tools  for  a  Gear  Wheel  —  Allowances  for 
Shaving  —  Nests  for  the  Work  —  Other  Designs  of  Shaving  Tools  —  A 
Piloted  Shaving  Die  —  Inverted  Shaving  Dies  —  Comparative  Advantages  of 
Dies  —  Piercing  and  Shaving  Cam  Slots  —  Blanking  and  Piercing  Centers 

—  The  Punch  Parts  —  The  Adjustable  Nest  —  Special  Nest  for  a  Thick 
Blank  —  Other  Forms  of  Dies. 

CHAPTER  VII.     Trimming  Dies  —  Trimming  and  Shaving 141 

General  Advantages  —  Simple  Trimming  Dies  —  A  ^Trimming  and  Shav- 
ing Operation  —  Shaving  Cams  —  Another  Trimming  and  Shaving  Die 

—  Dies  for  Piercing  and  Trimming  —  Application   of  the   Knock  Out  — 
Operations  on  a  Tube  —  Adjustable  Trimming  and  Shaving  Dies  —  Con- 
struction of  Trimming  Dies  —  The  Cutting  Edges  —  Trimming  and  Shav- 
ing Dies  of  the  Progressive  Order  —  Some  Details  of  Construction  —  The 
Form  of  the  Punches. 

CHAPTER  VIII.  DRAWING  DIES  AND  THEIR  ACTION  UPON  MATERIALS  ...  163 
Limiting  Factors  —  Action  of  the  Tools  Upon  the  Work  —  Displacement  of 
the  Metal  —  Application  to  the  Solid  Disk  —  The  Lines  of  Movement  — 
The  Drawing  Edge  of  the  Die  —  General  Types  of  Drawing  Dies  —  Prin- 
ciples of  Double  Action  Tools  —  Triple  Action  Dies  —  Die  for  Drawing 
Shells  —  Die  Shoes  and  Punch  Holders  —  Form  of  the  Dies  —  Smaller 
Work  —  Proper  Vent  for  Punch  —  One  Method  of  Cupping  Thick  Metal 

—  Comparison  of  Die  Edges  —  Annealing  and  Pickling  of  Brass  Shells  —  Care 
Necessary  in  Annealing  —  The  Pickle  Bath  —  Effect   of  the   Acid  Upon 
the  Tools  —  Experience  with  Steel  Shells  —  Two  Methods  of  Drawing  Deep 
Flanged  Shells  —  An  Alternative  Method  —  The  Pinch  Off  Type  of  Punch 
and  Die  —  Other  Applications  of  the  Pinch  Off  Principle  —  Making  a  Fun- 
nel Shaped  Shell  —  An  Irregular  Oil  Can  Spout  —  Peculiarities  of  Square 
Drawing  Dies  —  Drawing  Work  Inside  Out  —  Successive  Draws  —  Gang 
Drawing  Dies  for  Steel  Thimbles  —  Progressive  Dies  for  Automobile  Hubs 

—  The  Bulging  Process  —  Perforating  Operations  —  Drawing  Large  Work 
of  Aluminum  —  Cast  Iron  Dies  —  Larger  Dies  of  Cast  Iron. 

CHAPTER  IX.     COMBINATION  AND  COMPOUND  DIES  FOR  BLANKING,  DRAWING, 

FORMING  AND  PIERCING 215 

Pressure  Springs  and  Pads  —  Taper  Shell  Operations  —  Tools  for  a  Hemi- 
spherical Cup  —  Making  a  Shallow  Circular  Housing  —  Piercing  Tools  Com- 
bined with  Blanking  and  Drawing  Dies  — •  Dies  for  a  Valve  Spring  Cup  — 
Muffler  Cup  Tools  —  Set  of  Tools  for  a  Brass  Coupling  —  A  Brass  Bushing 
Outfit  —  Second  Operation  Dies  —  Drawing  Fine  Wire  Mesh. 

CHAPTER  X.     BENDING  AND  FORMING  TOOLS 236 

Use  of  the  Spring  Pad  or  Knock  Out  —  Bending  Two  Ears  on  a  Blank  — 
A  Double  Bending  Outfit  —  The  Pressure  Pad  on  the  Work  —  Knock  Out  for 


CONTENTS  IX 

PAGE 

Both  Punch  and  Die  —  Floating  Work  Supports  —  A  Flat  Forming  or  Curl- 
ing Operation  —  Spring  Forming  with  Sliding  Jaw  Dies  —  Progressive  Type 
of  Dies  for  Bending  —  Making  a  Strap  —  Application  of  the  Slitting  Principle 

—  A  Sectional  Construction  —  A  Word  About  Curling. 

CHAPTER  XI.     BENDING,  FORMING  AND  OTHER  DIES  APPLIED  TO  SPECIFIC  LINES 

OF  WORK 263 

Blanking,  Piercing  and  Forming  Tools  for  Typewriter  Work  —  Piercing 
Six  Holes  at  Once  —  Operations  on  the  Margin  Stops  —  Blanking  Die  Ar- 
ranged to 'Save  Stock  —  The  Bending  Tools  —  Bending  Tools  for  Typewriter 
Springs  —  Forming  the  Ribbon  Core  —  Dies  for  Calculating  Machine  Parts 

—  The  Blanking  Dies  —  Piercing  Eighteen  Holes  —  The  Die  Sections  and 
Punches  —  Stamping,  Forming  and  Embossing  —  Drawing  and  Forming  a 
Four-Sided  Cover  —  The  Drawing  Operations  —  The  Trimming  of  the  Ends 

—  The  Piercing  and  Forming  Tools  —  Coin  Register  Dies  —  End  Forming 
Dies  —  Final   Forming  Tools  —  Casing  for   Coin   Changer  —  Side   Closing 
Dies. 

CHAPTER  XII.     DIES  FOR  EMBOSSING,  MARKING,  RIVETING,  SWAGING  .   .  .    ,-^3C4 
An  Embossed  Crescent  —  Tools  for  a  Ring  —  Embossing  an  Aluminum  Plate 

—  A  Large  Set  of  Dies  —  A  Stamping  or  Marking  Die  —  Preparing  Type  Bars 
for  Riveting  —  A  Set  of  Riveting  and  Staking  Tools  —  Swaging  Dies  for  an 
Air  Rifle  Part  —  Swaging  a  Small  Bushing. 

CHAPTER  XIII.     INDEXING  AND  TRANSFER  DIES 324 

An  Indexing  Perforating  Die  —  Notching  a  Typewriter  Comb  —  Transfer 
Devices  —  Details  of  Various  Tools. 

CHAPTER  XIV.     THE  SUB  PRESS  AND  ITS  DIES 334 

The  Dies  of  the  Sub  Press  —  Types  of  Sub  Presses  —  Clock  Wheel  Die  for 
the  Sub  Press  —  Tools  for  a  Clock  Frame 

CHAPTER  XV.     PUNCH  AND  DIE  STANDARDS 342 

Standard  Parts  for  Plain  Dies  —  Parts  for  Pillar  Dies  —  Die  Shoes  and 
Punch  Holders  —  Standard  Guide  Pins  and  Bushings  —  Compound  Die 
Standards  —  Standardizing  a  Line  of  Typewriter  Dies  —  Location  of  Holes 
in  Bolsters  —  Compound  Die  Details. 

CHAPTER  XVI.     FINDING  THE  SIZE  OF  BLANKS  FOR  SHELLS  AND  OTHER  DRAWN 

AND  FORMED  WORK 360 

Plane  Surfaces  and  Cones  and  Spheres  —  Rules  for  Finding  Dimensions  of 
Circles  and  Squares  —  Tables  of  Shell  Blank  Diameters  —  Laying  Out  Blanks 
for  Rectangular  Drawn  Shells  —  Blanks  for  Tapered  Shells. 

CHAPTER  XVII.     LAYING  OUT  AND  MAKING  TEMPLETS  AND  DIES      371 

Making  and  Using  Simple  Templets  —  Some  Templet  Tools  —  Laying  Out 
and  Roughing  Out  Dies  —  Application  of  the  Spacing  Center  Punch  —  The 
Circle  Marking  Center  Punch  —  Drills  and  Drifts  —  Working  Out  Die  Open- 
ings —  Advantages  of  the  Adaptor  —  The  Filing  Process  —  Die-makers' 
Squares  —  Grinding  Out  Dies  —  Operations  on  Punches  —  Larger  Die 
Work. 


X  CONTENTS 

PAGE 

CHAPTER  XVIII.     LOCATING  HOLES  ACCURATELY  IN  DIE  WORK 396 

Application  to  Progressive  Dies  —  The  Button  and  Test  Indicator  —  Work 
on  Inserts  —  The  Precision  Layout  —  Precision  Drilling  Machine  —  How  the 
Precision  Layouts  are  Used  —  The  Use  of  Master  Plates  —  Examples  of 
Master  Plates 

CHAPTER  XIX.     MAKING  A  SET  OF  SHAVING  DIES     .    .    .    .    . "~ 408 

•  Working  Out  the  Die  Opening  —  Die  Details  —  The  Die  on  the  Bench 
Filer  —  Method  of  Broaching  the  Die  —  Lapping  the  Die  Opening  —  Oper- 
ations on  the  Punch  —  Indicating  and  Grinding  Punch  Shank  —  Drilling 
for  the  Screws  and  Dowels  —  Making  the  Nest  —  Finishing  the  Dowel  Pins 
—  A  Set  of  Die  Reamers. 

CHAPTER  XX.     SOME  HARDENING  PRINCIPLES  APPLIED  TO  DIES 420 

Differences  in  Hardness  of  Various  Areas  —  Hardness  Lines  on  Die  Face  — 
Die  Hardness  Affected  by  Proportion  —  Influence  of  Finish  on  Die  Hardening. 


PUNCHES  AND  DIES 

LAYOUT,   CONSTRUCTION  AND  USE 


CHAPTER  I 
PRESS  TOOLS  IN   GENERAL 

The  class  of  shop  equipment  commonly  known  as  press  tools  or  punches 
and  dies,  is  becoming  extended  into  so  many  lines  of  manufacture  and  in 
those  lines  assuming  such  constantly  increasing  aspects  of  importance, 
that  no  one  responsible  for  factory  output  or  in  any  way  connected  with 
design,  manufacture,  or  tool  department  activities  can  afford  at  the  present 
time  to  remain  uninformed  in  respect  to  the  details  of  construction  and 
application  of  these  tools  if  the  product  of  the  plant  is  of  such  character  as 
to  admit  of  the  utilization  of  sheet  metal  working  apparatus.  And,  it 
may  be  added,  there  are  to-day  very  few  lines  of  metal  manufacture 
where  such  tools  cannot  be  employed  to  advantage,  even  though  in 
many  instances  their  complete  possibilities  are  not  recognized  and  appre- 
ciated until  a  detailed  study  has  been  made  of  existing  methods  in  the 
plant,  and  a  comparative  analysis  drawn  up  to  determine  what  parts 
may  be  converted  with  economy  into  press  manufactured  material. 

More  and  more  it  has  come  to  be  the  practice  to  produce,  by  some  form 
of  stamping  process,  work  that  formerly  was  almost  invariably  manu- 
factured from  the  solid  bar,  from  forgings,  or  from  some  other  class  of  solid 
material.  So,  in  addition  to  a  widely  diversified  line  of  products  that  have 
always  been  recognized  as  press  work  pure  and  simple,  there  have  developed 
numerous  other  classes  of  metal  parts  whose  manufacture  has  been  trans- 
formed from  the  conventional  operations  of,  say,  turning,  drilling,  and  so 
on,  to  the  processes  available  under  press  working  methods.  It  therefore 
is  quite  within  the  truth  to  state  that  the  time  is  already  here  when  no 
progressive  individual  connected  with  metal  parts  production,  whether  in 
drawing  office  or  shop  departments,  can  consistently  refrain  from  persistent 
investigation  of  current  practice  in  press  working  operations,  which,  though 
often  fundamental  in  character,  display  in  details  of  application  distinct 
advance  over  the  methods  of  the  past,  with  corresponding  progress  as 
measured  by  quality  and  volume  of  output. 

1 


2  V  ;  VENGHES  AND  DIES 


:'  OF  PRESS  USES 

Where  formerly  it  was  the  occasional  or  the  specialized  shop  that  made 
use  of  press  working  methods,  at  the  present  time  it  is  the  exception  to  find 
a  well  organized  plant  engaged  in  small  or  medium  parts  production  that 
does  not  find  it  necessary  to  utilize  metal  working  presses  to  a  considerable 
extent.  Even  where  very  large  articles  are  produced  from  sheet  metal  an 
important  percentage  of  the  work  and  frequently  the  whole  of  it  is  ac- 
complished by  the  blanking,  drawing,  forming,  and  other  processes  of  the 
press  department. 

As  a  natural  consequence,  the  rather  unusual  occupation  of  the  die 
maker  of  early  times  is  to-day  followed  by  a  great  number  of  tool  makers 
who  have  entered  upon  this  highly  skilled  branch  of  shop  work  and  whose 
handicraft  is  to  be  noted  in  tool  rooms  innumerable  throughout  the  country. 
Similarly,  the  tool  designers  over  the  drawing  boards  in  our  plants  are  de- 
voting more  and  more  attention  to  the  consideration  of  progressive  methods 
of  handling  sheet  metal  through  dies  of  various  classes,  and  these  men,  like 
those  in  the  tool  room,  exhibit  an  increasing  degree  of  interest  in  the  general 
subject  of  press  tools. 

Owing  to  the  fact  that  punch  press  operations  are  peculiar  to  them- 
selves, and  the  tools  cf  this  branch  quite  incomparable  with  other  special 
apparatus  about  the  shop,  emy  book  treating  upon  the  general  subject 
forming  the  title  of  the  present  volume  must  necessarily  deal  to  a  certain 
extent  with  some  few  details  of  a  fundamental  character;  details  possibly 
of  common  knowledge  to  such  tool  makers  and  draftsmen  as  have  long 
specialized  upon  work  of  this  nature,  but  none  the  less  important  however 
to  men  who,  with  perhaps  many  years  of  experience  in  other  skilled  branches 
of  the  machine  industry,  have  had  limited  opportunity  for  following  the 
advance  gained  in  the  punch  and  die  makers'  art.  Still,  from  their  ranks 
must  come  many  of  the  die  makers  of  the  immediate  future  and  therefore 
in  this  book,  along  with  examples  of  what  leading  mechanics  consider  their 
best  practice  in  press  tool  work,  a  little  space  will  be  devoted  to  certain 
elementary  considerations. 

GENERAL  CLASSES  OF  DIES 

First,  when  we  speak  of  diet,  we  mean  just  as  when  we  refer  to  press 
tools,  both  punches  and  dies.  Often  we  mention  a  set  of  dies,  meaning 
usually,  as  before,  a  punch  and  a  die.  While  ordinarily  the  die  is  secured  to 
the  bed  of  the  press  or  to  the  bolster  thereon,  and  the  punch  carried  above 
by  the  traveling  ram  or  slide  of  the  press,  this  arrangement  is  by  no  means 
universal,  for  in  many  instances  marked  advantages  of  operation  are  de- 
rived by  inverting  the  usual  order  and  placing  the  punch  below  and  mount- 
ing the  die  upon  the  slide  above.  And  in  compound  dies,  as  they  are 


PRESS  TOOLS  IN  GENERAL 


o3 


.2 


4  PUNCHES  AND  DIES 

called,  we  have  before  us  a  common  example  of  a  set  of  press  tools  in  which 
the  die  proper  carries  also  a  punch:  while  the  opposite  tool,  the  punch 
proper,  carries  a  die  inside.  So  in  neither  case  of  upper  or  lower  tool  in  the 
set,  considered  as  a  whole,  can  one  be  distinguished  entirely  as  a  die  and 
the  other  as  a  punch  for  each  half  combines  the  functions  of  both  punch 
and  die. 

However,  no  matter  what  the  relative  positions  of  the  punch  and  die 
may  be  or  how  the  two  tools  may  be  arranged,  we  may  safely  define  the 
die  as  the  tool  that  establishes  the  external  form  of  the  work  or  of  the 
opening  in  a  pierced  piece,  and  the  punch  as  the  corresponding  internal 
member. 

In  considering  press  tools  as  a  whole  it  is  of  value  to  note  how  they  fall 
into  certain  classes  as  distinguished  by  the  character  of  their  action  upon 
the  metal  which  is  manipulated  in  their  operation.  It  should  be  under- 
stood here  that  although  reference  is  distinctly  made  to  metal,  numerous 
other  materials  are  worked  by  identically  the  same  processes  as  the  various 
sheet  metals  such  as  iron,  steel,  brass,  copper,  aluminum,  german  silver,  tin, 
zinc,  etc.  These  other  materials  would  include  such  as  hard  fiber,  rubber, 
card  board,  leather,  paper,  mica,  fabrics,  and  so  on.  Not  but  what  spe- 
cial modifications  must  be  made  in  many  instances  where  press  tools  are 
applied  to  manufacture  of  parts  from  these  substances,  but  in  their 
principal  characteristics  the  tools  used  are  identical  with  or  quite  similar 
to  those  employed  on  sheet  metal  operations,  many  examples  of  which 
are  seen  in  Fig.  1. 

How  TOOLS  MAY  BE  CLASSIFIED 

If  now  we  group  the  various  forms  of  press  tools  according  to  their 
action  upon  materials,  we  shall  find  that  in  general  they  may  be  classified 
under  four  heads  as  follows: 

I.  Tools  that  operate  by  cutting  or  "shearing"  the  metal,  for  example, 
blanking  dies  (Figs.  2  and  3),  shearing  or  cutoff  dies,  notching  dies,  etc. 

II.  Tools  that  shape  the  article  by  drawing  the  material,  causing  it  to 
"flow"  under  tension  as  in  the  instances  of  cupping  dies,  drawing  dies, 
bulging  dies,  and  so  on. 

III.  Tools  that  manipulate  the  stock  or  the  blank  already  cut  out,  by 
some  form  of  bending  process.     In  this  class  come  simple  and  compound 
bending  dies,  forming  dies,  and  the  like. 

IV.  Tools  that  by  compressing,  squeezing,  or  forcing  the  material 
cause  it  to  "flow"  into  the  desired  form  as  when  acted  upon  by  swaging 
dies,  extruding  dies,  coining  dies,  etc. 

In  Class  I  may  be  included  the  following  tools:  Blanking,  Piercing, 
Shaving,  Notching,  Shearing,  and  Trimming  Dies.  Also  Hollow  Cutting 
or  "Dinking"  dies,  so  called,  belong  in  this  general  class,  although  made 


PRESS  TOOLS  IN  GENERAL 


not  for  working  metal,  but  rather  for  cutting  out  leather,  card  board, 
fabrics,  and  other  materials  either  by  hand  or  machine  processes. 

Class   II  includes  Cupping,  Drawing,  Redrawing,  Bulging,  and  Re- 
ducing Dies.    Strictly  speaking  the  latter  tools  do  not  draw  or  "stretch" 


FIG.  2.  —  Blanking  punch  and  die  "open"  type 


The  Piece 
Blanked 


PLAN  OF  DIE 

FIG.  3.  —  Detail  of  open  punch  and  die 


the  metal,  but  rather  act  in  an  opposite  manner  to  close  or  taper  a  shell, 
say,  already  drawn  out  to  required  length  and  body  size.  Their  operation 
is  thus  so  closely  allied  to  that  of  drawing  and  their  design  so  similar  that 
they  may  be  grouped  in  the  same  class  as  the  usual  drawing  die. 


6  PUNCHES  AND  DIES 

Class  III,  which  covers  various  forms  of  Bending  and  Forming  Dies, 
may  also  include,  under  certain  circumstances,  Curling  and  Wiring  Dies. 
That  is,  when  the  operations  of  curling,  or  of  curling  and  wiring  combined, 
are  applied  in  the  manufacture  of  flat  parts  whose  ends  or  edges  are  curled 
or  rolled  up,  the  process  is  one  closely  akin  to  forming  as  conducted  with 
dies  having  side  closing  members  which  catch  the  edges  of  the  blank  and 
turn  or  curl  it  over  as  desired. 

Where  Curling  or  Wiring  operations  are  applied  to  such  articles  as  are 
drawn  up  to  cylindrical  or  conical  form,  as  in  the  cases  of  cups,  utensils,  or 
other  objects  requiring  curling  around  the  open  end,  the  Curling  and  Wiring 
tools  come  within  Class  II  as  the  processes  are  those  involving  stretching 
and  drawing  over  of  the  annular  surface  about  the  mouth  of  the  work. 

Class  IV  comprises  Swaging,  Heading,  Riveting,  Staking,  Embossing, 
Coining,  Extruding  Dies. 

Then  there  are  miscellaneous  tools  that  according  to  individual  cir- 
cumstances may  or  may  not  be  grouped  under  some  one  or  other  of  the 
above  heads:  These  include  Flattening  or  Straightening  Dies,  Marking  or 
Numbering  Dies,  Staking  Dies,  Crimping  Dies,  Burnishing  or  Sizing  Dies, 
Assembling  Dies,  etc. 

VARYING  ARRANGEMENT  OF  TOOLS 

All  of  the  dies  in  the  different  groups  are  made  in  great  variety  and  in 
many  instances  they  are  combined  one  with  another  so  that  oftentimes 
one  set  of  tools  may  incorporate  in  its  construction,  two,  three,  or  four 
distinct  classes  of  dies  for  performing  as  many  individual  operations  upon 
the  work  at  a  single  pass  through  the  press.  Such  tools  are  variously 
known  as  Progressive  Dies,  Follow  Dies,  Cut-and-Carry  Dies,  Step-Along 
Dies,  Multi-Stage  Dies,  Tandem  Dies,  and  so  on;  in  any  event  the  term 
applied  indicates  the  system  of  passing  the  work  along  through  successive 
stages  in  the  one  set  of  tools.  A  set  of  progressive,  piercing,  and  blanking 
dies  with  bolster  and  work  will  be  seen  in  Fig.  4. 

Also,  the  different  types  of  tools  such  as  blanking  dies,  piercing  dies, 
etc.,  are  frequently  made  to  blank  out  several  pieces  at  once  or  to  punch  a 
series  of  holes  at  one  stroke  of  the  press,  such  tools  then  being  designed  as 
Gang  or  Multiple  Dies  and  Gang  or  Multiple  Punches.  In  the  case  of  the 
latter  where  a  considerable  number  of  very  small  holes  are  pierced  at  once, 
the  tools  are  commonly  known  as  Perforating  Dies. 

Now,  with  nearly  all  of  the  types  of  tools  grouped  under  the  foregoing 
definite  classes,  there  is  a  distinction  based  upon  general  relationship  be- 
tween punch  and  die,  that  is,  upon  the  method  of  construction  whereby 
alinement  is  secured  between  the  two  members  in  any  given  set  of  tools. 
This  may  be  briefly  referred  to  at  this  point  and  considered  more  in  detail 
in  another  chapter. 


PRESS  TOOLS  IN  GENERAL 


FIG.  4.  —  Progressive  piercing  and  blanking  tools 

THE  SUB  PRESS  DIE 

It  was  formerly  the  universal  practice  to  construct  press  tools  with  no 
positive  provision  whereby  fixed  alinement  of  punch  and  die  was  secured, 
and  in  setting  up  the  tools  in  the  press,  after  the  punch  had  been  fastened 
in  the  ram  or  slide,  considerable  care  and  skill  were  necessary  to  so  adjust 
the  die  on  its  bolster  as  to  bring  the  die  open- 
ing into  exact  position  under  the  end  of  the 
punch.  Frequently,  after  the  tools  were  so 
set,  there  arose  possibility  of  the  die  shifting 
slight!}'  during  continued  operation,  and  this 
led  to  what  is  known  as  "shearing"  of  the 
cutting  edges  of  the  die  or  of  both  tools 
together,  an  action  resulting  in  more  or  less 
serious  injury  to  the  dies  and  occasional  chip- 
ping or  breaking  beyond  remedy  by  the  simple 
process  of  regrinding. 

Eventually,  and  particularly  among  makers 
of  clocks,  watches,  and  other  small  appara- 
tus, what  is  called  the  Sub  Press  came  into 
use  and  we  now  find  in  nearly  all  shops  doing 
good  press  work,  some  form  of  sub  press  die 
construction  which  not  only  eliminates  the 
difficulties  referred  to  but  further  assures  a  much  higher  grade  of  product 
generally. 

The  Sub  Press  now  long  in  service  consists,  as  its  name  indicates,  in  a 
small  press,  Fig.  5.  which  is  slipped  bodily  into  the  regular  power  press  or 
hand  press  and  there  operated  by  connecting  its  plunger  with  the  slide  of 


FIG.  5.  —  Cylindrical  sub  press 
with  dies  for  a  watch  wheel 


8 


PUNCHES  AND  DIES 


the  press.  Its  plunger  is  always  in  alinement  with  its  base,  and  the  seats 
in  plunger  and  base  for  the  punches  and  dies  assure  fixed  alinement  of  the 
latter  at  all  times. 

The  principle  of  the  sub  press  has  been  extended  in  later  times  to  em- 
brace press  tools  of  all  sizes,  but  ordinarily  in  such  cases  we  now  see  on 
most  work  aside  from  the  very  smallest,  and  frequently  on  that  as  well, 
not  the  original  type  of  sub  press  proper,  but  what  we  know  as  Sub  Pressed 
Dies,  or  Pillar  Sub  Press  Dies,  or  again,  Corner  Post  Dies. 

The  term  Pillar  Die  is  perhaps  the  best  known  and  the  most  accurate 
designation,  for  its  guide  posts  or  pillars  may  or  may  not  be  located  at  the 
corners,  according  to  circumstances.  In  any  case,  the  arrangement  con- 
sists of  two  or  four  round  guide  rods  fixed  in  the  die  block  and  passing  up 
through  holes  bored  in  the  punch  holder,  thus  preserving  alinement  of  both 
members,  so  that  the  set  of  tools  are  always  in  correct  relative  position  and 

whether  in  or  out  of 
the  press  are  handled 
as  a  complete  unit 
without  liability  of 
injury.  Thus  they 
maintain  their  accu- 
rate working  qualities 
and  facilitate  setting 
up  and  production 
operations  in  many 
ways. 

A  WORD  ABOUT  SEC- 
TIONAL DIES 

In  general  die  con- 
struction, there  is  yet 
another  point  in  which 
practice  differs  in  re- 
spect to  the  design  of  the  tools  and  according  to  the  shop  where  used  or 
the  size  of  the  work  produced.  As  dies  become  more  intricate  in  char- 
acter, or  of  increased  dimensions,  the  original  one-piece  form,  with  the 
die  and  punch  each  worked  out  from  the  solid  metal,  is  replaced  by  sec- 
tional construction  in  which  a  number  of  pieces  enter  into  the  make  up  of 
the  tools  proper.  In  simplest  form  such  tools  are  "split"  dies,  made  in 
halves  as  in  Fig.  6.  In  some  instances  several  hundred  pieces  are  included 
in  a  single  die,  which,  were  it  not  for  the  sectional  design,  it  would  be  im- 
possible to  construct  in  the  first  place,  or.  if  once  built,  it  would  prove  im- 
practicable to  maintain  in  working  condition  for  any  extended  period. 
While  in  the  smaller  sizes  such  tools  are  ordinarily  made  up  of  steel, 


FIG.  6.  —  Sectional  die  made  in  halves 


PRESS  TOOLS  IN  GENERAL  9 

except  for  their  holders  or  bases,  there  are  numerous  cases  where,  aside 
from  working  edges,  all  other  parts  are  of  machine  steel,  cast  iron,  or,  in 
some  instances,  even  of  wood.  In  fact,  in  various  examples  of  solid  dies 
as  well  as  sectional,  cast  iron  has  been  employed  to  the  complete  exclusion 
of  tool  steel,  particularly  in  drawing  and  forming  operations.  Similarly, 
wood  dies  have  been  used  without  metal  protection  for  certain  forming 
processes. 

BLANKING  DIE  ACTION 

Of  the  various  kinds  of  press  tools  in  service,  blanking  dies  are  among 
the  most  commonly  employed,  perhaps  the  most  generally  used  of  all, 
unless  it  may  be  with  one  possible  exception,  the  piercing  tool,  commonly 
called,  in  elementary  form,  a  punching  die.  The  characteristics  of  the 
blanking  die  and  of  the  piercing  die  are  almost  identical  in  respect  to  their 
action  upon  the  work,  and  we  have  only  to  consider  a  piercing  tool  of  fair 
diameter  as  compared  with  the  outside  of  the  blank,  to  recognize  the  fact 
that  the  piercing  punch  is  merely  an  internal  blanking  tool  whose  purpose 
it  is  to  form  an  accurate  opening  in  the  stock  by  cutting  out  a  blank  which 
is,  however,  discarded  as  the  scrap  or  "slug"  from  the  punch,  just  as  the 
material  around  the  outside  of  the  blank  is  the  scrap  from  the  blanking 
dies. 

Considering,  now,  a  simple  blanking  punch  and  die  or  a  set  of  blanking 
tools,  or  again,  a  set  of  blanking  dies,  if  so  preferred,  we  have  in  Fig.  2  a 
typical  illustration,  and  in  Fig.  3  a  drawing  which  shows  the  respective 
parts  of  both  punch  and  die,  including  the  bolster  upon  which  the  die 
proper  is  secured,  the  stripper  which  prevents  the  stock  from  lifting  with  the 
upstroke  of  the  punch,  the  stock  stop  which  limits  the  forward  movement 
of  the  strip  of  metal  after  each  punch  stroke  and  the  guide  against  which 
the  stock  is  held  to  secure  straight  movement  through  the  die.  The  shape 
of  the  blank  produced  is  also  shown  clearly  by  the  engraving. 

THE  CUTTING  EDGES 

If  we  consider  the  metal  to  be  blanked  as  very  thin  stock,  it  is  easily 
seen  that  the  action  of  the  edges  of  the  punch  in  respect  to  the  die  is  that 
of  a  cutting  tool,  or  we  might  say  of  a  pair  of  shear  blades  severing  a  piece 
of  paper  or  thin  tin.  As  stock  of  much  heavier  gage  is  taken  under  con- 
sideration, it  is  not  always  quite  so  easy  to  recognize  the  cutting  character 
of  the  press  tool  edges.  But  suppose  we  examine  the  tools  in  Fig.  7  for  a 
moment  and,  instead  of  passing  the  strip  of  metal  clear  across  the  face  of 
the  die  as  in  Fig.  3,  merely  slip  the  end  of  the  metal  over  the  edge  of 
the  die  opening  as  at  A,  Fig.  7.  Now,  if  the  material  is  fairly  heavy  as 
compared  with  the  size  of  the  dies,  the  punch,  when  it  strikes  the  surface 
of  the  stock  at  one  side  as  sketched,  will  naturally  have  a  tendency  to 
crowd  slightly  away  from  the  work  in  the  direction  of  the  arrowhead,  and 


10 


PUNCHES  AND  DIES 


bend  the  end  of  the  sheet  metal  down  a  trifle  as  indicated  at  B,  before  the 
cut  can  start.  If,  however,  we  bevel  the  face  of  the  punch  from  front  to 
back  as  at  C,  giving  its  cutting  edge  a  decided  degree  of  shear,  we  can  see 
at  once  that  the  sheet  metal  will  be  readily  severed  by  this  very  shearing 
action  of  the  punch  edge  past  the  die  edges. 


Punch   [stripper 

?gt^  Stock 


A  B  C 

FIG.  7.  —  Action  of  punch  and  die  on  the  stock 


E 


And,  sometimes  this  device  is  resorted  to,  by  the  die  maker,  where  cer- 
tain "conditions  obtain,  although  with  blanking  operations  this  feature  of 
cutting  along  one  edge  only  does  not  of  course  ordinarily  enter  in.  It  is 
referred  to  here  merely  for  the  purpose  of  illustrating  the  general  effect 

resulting  from  an  ordinary  flat  ended 
punch  striking  at  one  edge  only  on 
heavy  gage  material.  In  practice  the 
end  of  the  punch  comes  down  squarely 
as  at  D,  cutting  out  "the  blank  clean 
and  sharp  as  the  punch  edges  pass 
down  to  the  die.  With  heavy  stock, 
the  die  maker  sometimes  facilitates 
matters,  as  mentioned  above,  by  pro- 
viding true  shearing  action  on  the 
part  of  the  punch  from  one  end  to 
the  other,  or  as  at  E,  where  the  end 
of  the  latter  is  slightly  concaved.  Sometimes  the  die  itself  is  sheared  in- 
stead of  the  punch.  This  device  is  more  common  however  on  piercing 
punches  where  heavy  plate  is  punched,  the  edge  of  the  tool  in  that  case 
being  often  made  with  a  spiral  contour  which  shears  through  the  work  in  a 
relatively  gradual  manner. 

PIERCING  TOOLS 

Both  plain  flat-ended  and  spiral-cutting  piercing  punches  of  this  nature 
are  illustrated  in  Figs.  8  and  9  respectively.  The  type  of  die  shown  in 
Fig.  9  is  generally  known  as  a  punch  die  —  sometimes  as  a  button  die. 


FIG.  8.  —  Simple  piercing  dies 


PRESS  TOOLS  IN  GENERAL 


11 


Such  tools  are  often  made  with  very  small  punches  which  are  supported 
at  their  cutting  ends  by  passing  through  a  guide  plate  provided  with  holes 
in  which  the  punches  are  a  close  fit.  Also  radial  or  side  closing  punches 
are  made  for  piercing  work  through 
the  side.  While  we  are  apt  to  think 
of  piercing  dies  as  used  principally 
for  round  holes,  they  are  almost  as 
frequently  employed  for  making  other 
shapes  of  openings,  square,  oblong, 
irregular,  curved,  slotted,  etc.  Thus 
the  dies  that  cut  out  the  narrow 
curved  cam  slot  in  the  disk,  Fig.  10, 
are  piercing  tools  just  as  definitely 
as  though  they  were  adapted  for 
making  a  single  round  hole  in  the 
center  of  the  blank  or  a  series  of 
small  holes  through  any  part  of  the 
object. 


FIG.  9.  —  Plain  and  spiral  types  of 
punch  dies 


This  set  of  tools,  it  will  be  noticed,  are  of  the  subpressed  type,  or  pillar 
construction,  referred  to  on  a  preceding  page,  the  punch  and  die  being  held 


FIG.  10.  —  Dies  for  piercing  a  curved  slot 

in  definite  alinement  by  the  upright  posts  fixed  in  the  die  base  and  forming 
guides  for  the  punch  block  in  its  up  and  down  travel.  There  are  other 
important  features  of  these  tools  that  will  be  described  at  another  point 
in  this  volume. 


12  PUNCHES  AND   DIES 

NOTCHING  AND  COMB  DIES 

Notching  Dies  that  cut  out  a  series  of  straight  or  tapered  openings  in  a 
blank  as  in  Fig.  11,  are  other  forms  of  piercing  tools  used  on  electrical  and 
similar  work.  They  may  cut  at  one  time  a  complete  set  of  openings  around 
a  circle  or  a  segment,  or  they  may  be  used  with  an  indexing  device  for 
piercing  out  one  or  more  notches  at  a  time. 

Similarly  the  dies  that  cut  out  the  comb  shaped  slots  in  the  piece,  Fig. 
12,  are  types  of  piercing  devices  known  usually  as  Comb  Dies. 


FIG.  11  FIG.  12 

Work  performed  in  notching  dies 

SHAVING  TOOLS 

Shaving  Dies  are  employed  on  accurate  press  work  where  closest  di- 
mensions and  sharp  clean  edges  must  be  maintained  on  the  work.  These 
may  be  in  the  form  of  external  shaving  tools  for  finishing  around  the  outer 
edges  of  a  blank  produced  in  an  earlier  operation,  or  they  may  be  used 
with  equally  good  results  for  internal  cuts  as  in  finishing  the  edges  of  a  slot 
or  an  opening  of  any  shape  produced  by  piercing  tools. 

They  form  one  of  the  most  important  types  of  tools  for  assisting  the 
die  maker  to  secure  best  results  as  to  accuracy  of  product.  Ordinarily 
they  are  made  to  remove  a  very  thin  shaving  around  the  edge  of  the  blank, 
say  only  a  few  thousandths  at  the  most,  and  sometimes  reshaving  tools 
are  used  to  follow  the  first  shaving  dies,  to  insure  perfectly  smooth  and 
accurate  edges  on  the  blank.  If,  in  blanking,  too  small  an  allowance  is 
left  for  shaving,  it  is  not  always  possible  to  produce  a  perfectly  clean, 
smooth  contour;  and,  furthermore,  a  reasonable  allowance  tends  to  in- 
crease the  life  of  the  dies  by  permitting  them  to  take  a  clean  cut  around  the 
blank  without  likelihood  of  very  thin  chips  wedging  in  between  the  working 
faces  of  punch  and  die. 

Shaving  operations  are  usually  performed  by  dropping  a  blanked  piece 
into  a  nesting  or  locating  device  on  the  top  of  the  shaving  die.  Occasionally, 
however,  where  only  a  small  portion  of  a  piece  requires  shaving,  as  with 
some  important  working  surface  on  a  piece  that  is  otherwise  of  only  ordi- 
nary degree  of  accuracy,  the  shaving  operation  may  be  accomplished  before 
blanking  by  piercing  out  an  opening  in  the  stock  around  the  surface  to  be 
shaved,  then  shaving  the  accurate  portion,  and  following  by  blanking  out 
the  piece,  this  method  involving  the  use  of  a  progressive  or  follow  die  in 


PRESS  TOOLS  IN  GENERAL 


13 


which  the  three  operations  are  carried  on  at  once  for  as  many  pieces  after 
the  stock  has  been  advanced  clear  into  the  dies. 

A  shaving  die  of  interesting  construction  is  illustrated  by  Fig.  13,  from 
which  it  will  be  gathered  that  in  general  appearance  the  shaving  tools 


FIG.  13.  —  A  shaving  die  for  a  toothed  blank 

closely  resemble  blanking  dies  except  for  the  special  nesting  plate  placed 
over  the  die  proper  in  place  of  the  customary  stripper  required  for  blanking 
tools. 

CUTTING-OFF   OR   PARTING   DlES 


n 


Cutting-ofif  or  shearing  tools,  like  others  included  in  press  working 
operations,  are  constructed  in  various  ways  and  for  various  classes  of 
work.  In  simplest  form  they  are  employed 
for  severing  flat,  round,  and  other  stock,  and" 
often  are  fitted  with  other  tools  in  the  same  set 
of  dies  for  cutting  off  a  piece  from  the  strip  of 
stock  after  certain  other  operations  have  been 
performed. 

When   made   solely   for  cutting  across  a 
piece  of  metal  it  is  possible  to  give  their  edges 
considerable  "shear"  or  slope,  as  in  Fig.  14,  to  FIG-  14.  —  Punch  with  sheared 
enable  them  to  cut  more  freely,  if  desirable.  cutting  edge 

Oftentimes  they  are  shaped  to  give  some  special  curve  or  form  to  the  end 
of  the  piece  cut  off  and  a  similar  shape  to  the  leading  end  of  the  next 
piece.  Thus  the  tools  are  made  symmetrical  and  the  same  stroke  that 
cuts  off  the  last  end  of  the  one  piece  also  shapes  the  first  end  of  the  next, 


14 


PUNCHES  AND  DIES 


which  will  in  turn  be  cut  off  to  shape  when  the  stock  is  fed  forward  and 
the  punch  makes  its  next  down  stroke. 

This  design  balances  the  cut  on  opposite  sides  of  the  flat  ended  punch 
and  allows  a  single  tool  to  operate  on  the  ends  of  two  pieces  at  once. 

TRIMMING  DIES 

Trimming  dies  are  used  for  cutting  off  the  flange  or  the  extra  metal  on 
the  ends  or  edges  of  articles  that  have  been  made  by  some  kind  of  blanking, 

forming,  or  drawing  process  where 
an  irregular  edge  or  a  small  amount 
of  metal  in  the  nature  of  a  fin  has 
been  left  which  must  be  trimmed 
off  to  bring  the  work  to  finished 
condition.  An  example  of  such 
tools  as  applied  to  a  drawn  shell 
with  the  work  ready  for  trimming 
and  also  with  the  edge  finished  by 
passing  through  the  dies  is  seen  in 
Fig.  15.  The  punch  is  so  formed 
as  to  enter  the  drawn  work  and 
pass  it  down  through  the  die  with 
the  result  that  the  flared  open  edge  is  trimmed  smoothly  all  the  way  round. 
The  cutting  action  of  the  trimming  tools  is  like  that  of  an  ordinary  set  of 
blanking  dies  except  that  the  punch  is  really  piloted  to  enter  the  work  and 
support  it  during  the  movement  past  the  cutting  face  of  the  die.  Trim- 
ming dies  are  used  extensively  on 
flat  blanks  as  well,  and  also  for 
cutting  out  certain  portions  of  the 
edges  of  various  classes  of  parts, 
round,  square,  and  of  other  form. 


FIG.  15.  —  A  flange  trimming  die 


HOLLOW  CUTTING  TOOLS 

The  old  shop  term  Dinking 
Dies  applies  to  a  certain  type  of 
blanking  die  which  is  used  for 
many  materials  softer  than  sheet 
metals.  While  in  principle  they 


Brass  Face 
Tool  Steel 
Mach.  Steel 


FIG.  16.  —  Dies  for  blanking  fiber 


are  similar  to  some  forms  of  blanking  tools  for  metal  work,  they  differ  in 
having,  usually,  a  rather  keenly  beveled  cutting  edge  which  cuts  through 
the  material,  leather,  paper,  or  other,  in  the  same  free  manner  that,  to  em- 
ploy a  homely  comparison,  a  biscuit  cutter  passes  through  .the  rolled  out 
sheet  of  plastic  dough. 

Examples  of  tools  for  cutting  leather  and  fiber  are  included  in  Fig.  16. 


PRESS  TOOLS  IN  GENERAL 


15 


Their  edges,  according  to  the  material  to  be  cut,  are  commonly  sloped  to  an 
angle  of  twelve  to  twenty  degrees,  and  in  some  cases  the  interior  is  fitted 
with  some  form  of  ejecting  device  corresponding  closely  to  that  employed 
in  metal  working  dies  for  parts  of  similar  form.  The  punch  is  faced  with 
soft  brass  or  wood  according  to  the  material  to  be  cut. 

The  foregoing  examples  of  various  kinds  of  dies  for  blanking,  piercing, 
shaving,  etc.,  give,  in  skeleton  form,  some  of  the  essential  elements  of  the 
different  forms  of  press  tools  that  operate  by  cutting  or  shearing  the  ma- 
terial. They  will  be  taken  up  in  considerable  detail  in  other  sections  of 
this  book. 

We  may  now  turn  to  another  class  of  dies,  those  that  operate  by  draw- 
ing or  stretching  the  metal  from  the  flat  surface  to  the  special  form  desired. 

THE  DRAWING  PROCESS 

When  we  take  a  piece  of  flat  stock,  brass,  steel,  or  other  metal,  and  push 
it  through  a  round  die  by  means  of  a  dull  ended  punch  which  cannot  cut 
through  the  stock,  we  "draw"  the  blank  into  a  cylindrical  shell,  and  if  our 
punch  and  die  have  been  of  such  size  as  to  allow  for  the  full  thickness  of  the 


FIG.  17 


FIG.  17.  —  Drawing  dies 

•  i 

metal  between  the  punch  and  the  interior  of  the  die,  the  area  of  the  drawn 

shell  will  be  practically  that  of  the  plain  disc  blank  from  which  it  started. 
That  is,  the  operation  accomplished  is  one  of  simple  drawing  without 
appreciable  "stretching"  of  the  original  area,  although  the  form  of  the 
work  has  passed  through  a  decided  change  in  which  certain  elements  of 
the  metal  have  been  locally  closed  or  compressed  to  a  degree,  and  others 
directly  opposite,  stretched  correspondingly. 

Consider  for  a  moment  the  thin  disk  in  Fig.  17.  Say  we  have  a  brass 
blank  A  TV  inch  thick,  and  of  given  area,  we  can  force  it  down  through  the 
simplest  form  of  drawing  dies  at  B  and  produce  the  cup  C  which,  with  cer- 
tain proportions  between  punch  and  die,  will  have  practically  the  same 
total  area  as  the  round  blank  A.  By  repeating  the  drawing  operations 
with  smaller  dies  and  punches  we  reduce  the  diameter  of  the  cup  and  ex- 
tend the  length  into  a  short  shell  D  and  then  into  a  longer,  smaller  shell  E. 
Still,  it  is  usually  possible  if  necessary  to  hold  the  original  area  of  surface, 
indicating  that  under  such  conditions  while  the  metal  has  been  bent, 


16  PUNCHES  AND  DIES 

stretched,  and  compressed,  at  certain  portions,  the  general  body  of  the 
metal  has  not  been  stretched  as  a  whole. 

But,  in  usual  drawing  processes  it  is  desired  to  stretch  the  original 
metal  out  as  the  operations  proceed,  gradually  reducing  the  thickness  pro- 
portionately to  the  length  of  the  "draw"  and  generally  bringing  the  com- 
pleted shell  to  a  fairly  thin  section  as  compared  with  the  original  blank. 
Occasionally,  however,  metal  is  encountered  which  will  not  permit  of  marked 
if  any  reduction  in  thickness  by  the  drawing  process,  and  in  such  cases  the 
stock  is  selected  of  the  same  thickness  as  is  desired  for  the  finished  pro- 
duct. The  drawing  or  flowing  under  tension  of  the  thicker  metal  as  it  is 
thinned  down  by  being  elongated  in  the  drawing  dies  tends  to  harden  the 
material,  and  with  the  majority  of  work  where  a  number  of  drawing  opera- 
tions are  necessary  to  complete  the  piece  it  is  essential  to  anneal  the  shell 
between  successive  draws,  otherwise  the  stock  will  tear  apart,  or  the 
bottom  of  the  shell  be  punched  out,  an  indication  of  the  decided  degree  of 
tension  that  the  material  is  subjected  to  under  usual  conditions  of  drawing. 

ACTION  OF  DRAWING  TOOLS 

The  combined  action  of  the  punch  and  the  opposing  die  surface  tend 
to  "iron"  out  the  surface  of  the  metal  as  it  is  drawn  into  the  cup  form  and 
prevent  undue  wrinkling  during  the  shallow  draw.  As  the  cup  is  redrawn 
step  by  step  into  longer  shells,  in  successive  dies,  the  reduction  in  each 
stage  is  limited  and  with  properly  made  tools  undesirable  wrinkling  is 
avoided. 

Where  deep  draws  are  made,  and  particularly  where  blanks  of  the  larger 
sizes  are  drawn  up,  the  simple  drawing  tools  indicated  in  the  sketch,  Fig.  17, 
are  replaced  by  double  action  dies  which  operate  in  conjunction  with  a 
pressure  pad 'for  holding  the  blank  under  a  definite  degree  of  pressure  and 
ironing  it  out  as  it  is  pulled  under  the  pad  and  down  into  the  drawing  die. 
Such  tools  are  used  in  presses  which  have  an  outer  slide  for  carrying  the 
pressure  pad  and  gripping  the  blank,  while  an  inner  slide  carries  the  regular 
drawing  punch  down  into  the  die. 

There  is  also  a  class  of  drawing  tools  such  as  combination  dies,  and 
another  type,  compound  dies  (used  extensively  also  for  blanking  and 
piercing),  where  work  requiring  shallow  drawing  may  be  both  blanked  and 
formed  or  drawn  to  depth  and  pierced  if  so  desired  at  one  stroke  of  the 
machine,  the  tools  carrying  their  own  pressure  pads  and  being  used  in 
simple  presses.  These  types  of  dies  will  be  described  more  fully  in  their 

proper  places. 

REDUCING  DIES 

Reducing  dies,  as  pointed  out  before,  are  commonly  used  for  tapering 
and  reshaping  the  end  or  some  portion  of  a  shell  which  requires  a  neck 
smaller  than  the  body  of  the  work.  They  are  considered  as  a  special  form 


PRESS  TOOLS  IN  GENERAL 


17 


of  redrawing  die,  though  their  action  is  to  close  the  end  of  the  shell  to  a 
certain  extent  rather  than  to  lengthen  the  body  proper.  One  of  the  most 
common  types  of  dies  of  this  character  is  that  used  for  reducing  the  necks 
of  cartridge  cases,  as  in  Fig.  18,  where  a  plain  taper  form  is  imparted,  as  at 
A,  by  the  first  die  and  the  neck  com- 
pleted by  a  second  die  as  at  B. 


. 


BULGING  DIES 


Bulging  dies  act  in  the  opposite 
manner  to  expand  the  body  of  an 
article,  as  in  Fig.  19,  where  the  work 
is  shown  placed  over  a  plunger  in  the 
die  which  rests  upon  a  thick  body  of 
rubber  so  that  as  the  punch  descends 
and  forms  the  top  of  the  work  to  the 
desired  shape,  the  rubber  is  forced 
outward  by  the  compression  of  the 
plunger  head,  causing  the  shell  to  expand  outward  into  the  die  chamber. 
Upon  the  up  stroke,  the  rubber  returns  to  its  original  dimensions  and  the 
work  is  removed. 


FIG.  18.  —  Reducing  dies 


Plunger  for 

Expanding 

Rubber 


Shell  to  be 

Expanded 

in  Bulging  Die 


FIG.  19.  —  Bulging  dies 

Fluid  dies  are  sometimes  used  for  expanding  work  into  an  artistic  mold- 
like  device,  the  liquid  being  placed  in  the  shell  to  be  formed  and  the  plunger 
carried  by  the  press  then  acting  upon  the  fluid  to  force  the  hollow  shell  into 
the  design  formed  in  the  die  or  mold.  Both  the  mechanical  bulging  die 
and  the  fluid  type  are  employed  principally  for  soft  metals  and  are  seldom 
seen  in  the  general  shop,  although  both  types  are  occasionally  used  for 
steel  and  other  relatively  hard  materials. 


18 


PUNCHES  AND   DIES 
BENDING  AND  FORMING  TOOLS 


These  dies  are  made  in  great  variety  and  operate  upon  all  classes  of 
work.  In  simplest  form,  say,  in  the  case  of  a  plain  bending  die,  the  outline 
of  the  bend  which  is  to  be  imparted  to  the  blank  is  formed  on  punch  and 
die,  as  in  Fig.  20,  where  the  method  of  bending  a  simple  form  is  indicated. 
Where  a  more  intricate  form  is  required,  as  in  Fig.  21,  a  die  with  jaws  that 
close  in  from  the  side  is  employed  to  form  the  ends  of  the  piece  over  the 


FIG.  20.  —  Simple  bending  die 

sides  of  the  punch  which  controls  the  inside  of  the  work.  Such  work  is 
frequently  passed  through  two  sets  of  dies,  one  for  starting  the  outlines 
of  the  bend,  the  other  for  completing  the  work. 

Where  the  ends  of  a  flat  blank  are  to  be  formed  up  into  a  curl,  as  in  Fig. 
22,  similar  side  closing  jaws  or  dies  are  fitted  into  the  die  base  and  these 


FIG.  21.  —  Piece  formed  with  side  closing  die  FIG.  22.  —  A  curled  piece 

act  to  roll  over  the  end  of  the  blank  as  shown.  The  die  is  then  strictly  a 
curling  tool  and  if  it  should  further  include  provision  for  enclosing  a  piece 
of  wire  in  the  curled  portion  which  is  made  to  roll  up  around  the  wire,  the 
tools  would  become  curling  and  wiring  dies. 

It  is  usually  a  decided  advantage  and  often  strictly  necessary  to  start  a 
slight  curl  on  the  blank  itself  when  it  is  produced  in  the  first  place  in  order 
that  it  shall  curl  in  the  proper  direction  when  operated  upon  by  the  curling 
dies. 


PRESS  TOOLS  IN  GENERAL 


19 


A  curling  and  wiring  die  for  cylindrical  work,  where  a  curled  edge  with 
wire  stiff ener  is  required  on  a  shell  or  utensil,  is  represented  by  Fig.  23. 

The  construction  is  practically  the  same  whether  or  not  the  wire  is 
required,  except  that  the  mouth  of  the  die  for  the  wire  may  be  modified 
to  suit  the  diameter  of  the  wire  as  indicated  by  the  sketch. 


f 


The  Curled  and 
Wired 


Seat  in  Die 
for  Curling 

Ring  for 
Holding  Wire 


-  Springs  for 
Supporting  Ring 


FIG.  23.  — r  Curling  and  wiring  dies 

SWAGING  DIES,   EMBOSSING  DIES,  ETC. 

Coming  now  to  the  class  of  dies  that  operate  by  swaging,  or  working 
the  metal  by  upsetting,  flowing,  and  forcing  the  mass  into  special  forms 
desired,  we  may  consider  first  the  simple  swaging  die,  Fig.  24.  Such  dies 
are  used  for  shaping  the  edges  and  corners  of  blanks  already  punched  out, 


FIG.  24.  -  Swaging  dies 

and  in  this  illustration  the  swaging  dies  are  for  a  small  handle  which  is 
finished  properly  along  its  edges  by  placing  it  in  the  dies,  thus  saving  the 
trouble  of  grinding  or  filing  corners. 

A  great  deal  of  work  is  finished  in  this  manner,  the  swaging  process 
giving  a  suitable  rounded  shape  to  flat  sections  and  forming  corners  and 
edges  smoothly  and  to  a  neat  finish. 

Sometimes  where  numbers,  names,  or  other  markings  are  to  be  im- 


20 


PUNCHES  AND   DIES 


pressed  into  the  surface  of  a  blank  the  operation  is  combined  with  that  of 
swaging.  In  other  cases  the  characters  are  stamped  on  the  work  before  it 
is  blanked  out. 

EMBOSSING  DIES 

There  are  several  distinct  types  of  embossing  dies,  among  the  most 
commonly  employed  being  those  used  for  making  jewelry  and  similar 
manufactures.  The  making  of  such  dies  is  a  highly  specialized  art  of 
itself  which  hardly  falls  within  the  field  of  the  present  book.  The  die 
proper  is  struck  up  from  a  master  or  hub  which  is  an  exact  duplicate  of  the 
work  to  be  produced. 

Embossing  dies,  so  called,  for  operating  on  sheet  metal  parts  are  often 


Drawing  Punch 
—Blanking  Punch  and  Blank 
Blanking  Die        Holder 


The  Embossed 
Work 


Lower  Plunger 

of  Press 
FIG.  25.  —  Embossing  dies 

used  in  conjunction  with  blanking  tools  or  with  blanking  and  drawing 
tools  combined.  In  the  latter  instance,  what  are  known  as  triple  action 
dies  are  sometimes  employed,  these  being  operated  in  a  triple  acting 
press, 

A  set  of  dies  of  this  character  is  shown  in  Fig.  25,  in  sectional  view  to 
represent  all  parts  clearly.  The  press  has  double  slides  above  to  operate 
the  blanking  punch  and  the  drawing  punch  inside  of  the  latter,  and  under 
the  die  bed  is  another  slide  known  as  a  plunger,  which  actuates  the  em- 
bossing die  and  forms  the  impression  on  the  end  of  the  shell  drawn  up 
after  the  drawing  punch  has  carried  the  work  down  to  the  face  of  the  em- 
bossing die»  The  stripping  of  the  finished  work  from  the  drawing  punch  is 
accomplished  on  the  up  stroke  by  the  edge  A. 


PRESS  TOOLS  IN  GENERAL 


21 


COINING  DIES 

Coining  dies  form  another  special  line  of  tools  and  a  type  which  is 
operated  under  very  heavy  pressures  in  machines  of  the  embossing  press 
class  used  for  striking  up  jewelry,  medals,  and  many  other  lines  of  work 
where  clear  cut  designs  are  required  in  relief  on  the  surface  of  the  object. 

The  design  for  a  coin  is  cut  on  both  upper  and  lower  dies  A,  B,  as  repre- 
sented in  Fig.  26,  and  after  the  blank  C,  or  planchet,  as  the  coin  disk  is 
called,  has  been  struck  up,  the  lower  die 
rises  through  the  collar  or  surrounding  die, 
and  carries  the  completed  coin  to  the  top 
where  it  is  discharged  from  the  press. 


Retaining 
/Ring  or  Collar 


HEADING  DIES 

A  common  example  of  the  type  of  die 
used  for  heading  is  found  in  the  tool  used 


Coin  or  Medal 


Bottom  Die 


FIG.  26.  —  Coining  dies 


for  striking  up  the  heads  of  shells,  say,  for  cartridges,  and  similar  articles 
and  dies  of  this  character  are  most  frequently  employed  in  special  hori- 
zontal machines,  although  they  are  also  used  in  various  forms  in  regular 


&  m  i 

m   i  *$  itf  &  •** 


FIG.  27.  —  Tools  for  riveting  and  staking 

vertical  presses.     A  head  formed  on  a  cartridge  case  by  regular  heading 
dies  is  seen  in  the  illustration,  Fig.  18. 

RIVETING  AND  STAKING  DIES 

These  tools  are  used  for  fastening  parts  together  and  are  made  in  great 
variety  according  to  the  form  of  the  rivet  or  other  fastening  device  which 
is  to  be  operated  upon.  It  is  the  usual  custom  where  the  pin,  rivet,  or  post 


22 


PUNCHES  AND  DIES 


to  be  fixed  is  a  plain  round  piece,  to  speak  of  the  tools  as  riveting  dies,  and 
where  a  square,  rectangular,  or  irregular  shape  of  stud  or  holding  pin  is 
to  be  "set"  to  call  the  tools  staking  dies.  Riveting  the  operation  con- 
sists in  upsetting  the  end  of  the  pin  or  rivet  sufficiently  to  hold  the  parts 
securely.  Usually  staking  requires  ^but  a  single  stroke  or  blow  of  the  punch 
to  spread  the  metal  to  hold  the  pin  fast  in  the  hole  in  which  it  fits,  and 
generally  a  staked  pin  or  other  piece  is  flush  with  the  face  of  the  member 
in  which  it  is  set,  while  with  riveting,  strictly  speaking,  the  end  of  the 
rivet  projects  above  the  surface  sufficiently  to  permit  of  the  forming  of  a 

regular  head  under  the  application  of  the 
punch.  Both  riveting  and  staking  tools 
are  shown  in  Fig.  27. 

EXTRUDING  DIES 

These  tools  as  considered  for  punch 
press  operations  are  employed  for  such 
work  as  forcing  out  from  the  flat  surface 
of  a  blank,  a  pin  or  other  projection 
which  may  be  needed  for  pivoting  or 


FIG.  28.  —  Extruding  tools 


riveting  the  piece  to  some  other  member.  The  action  upon  the  material 
is  quite  like  that  of  embossing,  but  for  the  purpose  indicated,  the  metal 
caused  to  protrude  from  the  face  of  the  work  is  generally  a  small  pin  or 
plug-like  extension,  as  shown  by  Fig.  28  where  the  piece  is  seen  between 
the  punch  and  die.  The  rivet  or  plug  thus  left  projecting  from  the  surface 
is  integral  with  the  body  of  the  metal  and  forms  a  secure  and  convenient 
device  for  the  purpose  of  locating  or  fastening  the  piece  to  some  other  part, 
or  for  receiving  some  other  member  that  is  required  to  operate  upon  a  post 
or  stud. 

The  action  of  the  extruding  punch  upon  the  metal  is  to  cause  it  to  flow 
ahead  into  the  die  and  with  properly  made  tools  a  clean  accurate  project- 
ing pin  is  formed  which,  for  various  purposes,  has  many  advantages  over 
the  more  common  rivet  as  usually  employed. 


CHAPTER  II 

BLANKING  DIES 

• .  •  • 

Blanking  dies,  the  most  commonly  used  of  all  press  tools,  are  made  for 
an  infinite  variety  of  parts  and  for  work  of  all  sizes  from  very  small  pieces 
to  large  rectangular,  circular,  and  other  forms,  ranging  sometimes  up  to 
several  feet  in  length  or  diameter.  In  elementary  form,  blanking  tools 
consist  merely  of  a  simple  punch  and  die  of  the  kind  illustrated  in  Fig.  2, 
in  the  preceding  chapter,  but  as  developed  for  larger  work  and  particu- 
larly for  parts  of  irregular  outline,  they  assume  more  intricate  forms  and 


FIG.  29.  —  Examples  of  blanked  parts 

are  oftentimes  made  up  of  a  large  number  of  sections  fitted  together  to 
cover  the  entire  outline  of  the  blank,  the  sectional  design  having  many  ad- 
vantages in  first  construction  and  later  on  in  the  upkeep.  This  form 
of  die  will  be  described  in  detail  in  the  present  chapter. 

First,  however,  certain  characteristic  sets  of  blanking  tools  for  small 
parts  will  be  illustrated,  such,  for  example,  as  are  employed  for  producing 
blanks  similar  to  some  of  the  pieces  represented  herewith  in  Fig.  29.  This 
group  of  blanks  for  calculating  machine  parts  is  composed  of  a  variety 
of  small  shapes,  and  as  this  chapter  continues,  other  and  larger  pieces 
blanked  by  similar  means  will  be  shown,  in  connection  with  the  dies 
with  which  they  are  made. 

23 


24  PUNCHES  AND  DIES 

BLANKING  AND  OTHER  OPERATIONS 

% 
It  has  been  pointed  out  that  blanking  operations  are  often  combined 

with  other  processes;  thus  piercing  and  blanking  dies  are  very  commonly 
combined  in  the  one  set  of  tools,  and  various  forms  of  blanking  and  drawing 
dies,  blanking  and  forming  tools  and  other  sets  for  performing  two  or  more 
operations  in  one  pair  of  dies  are  used  in  common  practice.  The  present 
chapter  however  will  be  restricted  to  blanking  dies  as  such,  without  refer- 
ence at  this  point  to  the  numerous  forms  in  which  they  are  made  up  as 
one  pair  of  dies  which  carry  also  piercing,  drawing  or  other  tools. 

Furthermore,  it  will  be  left  to  another  section  of  this  book  to  illustrate 
certain  interesting  examples  of  blanking  dies  which  constitute  first  opera- 
tion tools  in  complete  sets  of  dies  where  the  blanking  process  is  followed  in 
other  tools  by  such  operations  as  piercing,  bending,  forming,  drawing  and 


FIG.  30.  —  A  set  of  open  blanking  dies 

so  on.  In  this  connection,  the  blanking  dies  will  be  described  in  their  re- 
spective relationship  to  the  other  tools  in  the  series,  and  the  effect  which 
subsequent  operations  have  upon  the  design  of  the  blanking  tools  will  be 
discussed  fully. 

We  may  now  take  up  certain  types  of  blanking  dies  by  themselves  and 
consider  various  details  pertaining  to  their  construction.  In  order  to  bring 
out  different  points  of  importance  a  number  of  examples  have  been  selected 
representing  the  practice  of  several  shops  where  punch  and  die-making 
forms  a  very  large  part  of  the  tool  room  work. 
% 

SIMPLE  OPEN  DIE 

The  set  of  tools  in  Figs.  30  and  31  is  for  blanking  out  an  aluminum 
piece  of  triangular  form  to  the  dimensions  on  the  sketch,  Fig.  32.  The 
thickness  of  the  piece  is  approximately  &  inch  or  No.  16  B.  &  S.  gage.  It 
is  a  blank  which  is  afterward  bent  up  into  a  U-form,  but  the  material,  gage 
and  purpose  of  the  blank  are  of  no  especial  importance  here  as  the  illus- 


BLANKING  DIES 


25 


trations  are  merely  to  show  a  simple  form  of  blanking  die,  of  the  open 
type,  that  is  without  guide  pins,  and  to  represent  the  different  parts  in 
detail. 

These  parts  are  clearly  shown  in  Fig.  31  where  the  die  is  taken  apart. 
The  supports  for  the  stripper  plate  will  be  best  seen,  however,  in  the  other 


FIG.  31.  —  Blanking  tools  taken  apart 

view,  Fig.  30.     They  are  simply  short  bushings  which  hold  the  stripper 

at  the  right  distance  a5ove  the  die  face  and  allow  the  attaching  screws 

to  pass  through.     This  is,  of  course,  only  one  way  of  spacing  the  stripper 

above  the  die.     It  is  much  more  common 

practice  to  use  a  strip  of  metal  at  front  or 

back  or  along  both  edges,  to  hold  the  strip-    y,  A/£       X^VM  Thick 

per;  or  to  make  the  stripper  from  heavier 

metal  and  cut  out  a  channel  in  its  under 

side  to  allow  the  stock  to  be  fed  through. 

STOCK  STOPS 

The  die  illustrated  in  these  views  also 
carries  one  of  the  simplest  forms  of  stock 

stops,  a  short  projecting  pin,  bent  down  at    FlG-  32-  ~  The  blank  Produced  in 

,  f,    ',   -,  •    .  ,u      ,.  the  tools  in  Fig.  31 

the  outer  end  as  seen  at  the  left  of  the  die 

in  Fig.  30.  This  stop  is  attached  to  the  stripper  and  its  position  is  such  as 
to  enable  its  bent  end  to  engage  with  the  openings  punched  in  the  strip 
of  material  as  the  blanks  are  produced  one  by  one  and  the  stock  advanced 
step  by  step  to  the  left  in  being  fed  through  the  dies. 

The  details  of  stock  stops  in  numerous  forms  and  nests  or  locating 
devices  for  second  operation  dies  are  sufficiently  important  to  justify 
special  description  which  will  be  accorded  them  with  various  other  die 
details  in  other  chapters. 


26 


PUNCHES  AND  DIES 


It  will  be  noticed  that  the  punch  proper  in  Fig.  31  is  adapted  to  be 
attached  to  the  shank  by  means  of  fillister  head  screws.  Here  is  another 
detail  in  respect  to  which  there  is  wide  divergence  in  the  practice  of  dif- 
ferent shops.  A  common  method  is  to  make  the  punch,  if  not  too  large, 
with  a  solid  shank  if  the  dies  are  of  the  open  type  here  shown,  and  fit  the 
shank  either  directly  into  the  press  slide  or  into  an  auxiliary  shank  or 
adapter  which  itself  enters  the  slide  of  the  press.  Practice  in  this  respect 
and  with  other  details  of  punches  and  dies  will  be  taken  up  in  due  course. 


FIG.  33.  —  A  wheel  blanking  die  of  the  sub-press  type 
A  PILLAR  DIE 

Turning  now  to  blanking  tools  of  the  pillar  type,  that  is  with  guide  pins 
to  preserve  alinement  between  punch  and  die,  so  that  they  are  operated  on 
the  sub-press  principle,  we  have,  in  Figs.  33  and  34,  an  interesting  example. 
This  is  a  wheel  die  for  a  small  toothed  blank  with  outside  diameter  of 
TV  inch,  and  13  teeth.  It  is  of  cold  rolled  steel  0.090  inch  thick,  or  rather 
heavy  metal  for  so  small  a  blank.  Several  blanks  are  included  in  the 
group  referred  to  in  connection  with  Fig.  29  and  others  will  be  seen  in  the 
two  tool  photographs,  Figs.  33  and  34. 

The  pillar  die,  or  sub-pressed  die,  is  by  no  means  confined  to  operations 
on  small  work  of  the  kind  here  shown.  As  already  stated,  modern  practice 
in  press  tool  work  tends  to  a  rapid  adoption  of  this  form  of  die  for  large  as 


BLANKING  DIES 


27 


well  as  small  pieces,  and  not  only  for  blanking  operations  but  for  shaving, 
piercing,  forming,  and  other  press  processes. 

The  pillar  die  has  indeed  become  so  generally  used  for  a  great  variety 
of  press  work  that  a  majority  of  the  illustrations  in  this  book  will  be  con- 
fined to  examples  of  that  form  of  construction. 


FIG.  34.  —  Punch-head  removed  from  guide  pins 

WHEEL  DIE  DETAILS 

A  drawing  of  the  wheel  die,  Fig.  33,  is  reproduced  in  Fig.  35.  This 
shows  all  details  clearly  and  brings  out  distinctly  the  method  of  locating 
the  punch  in  the  head  or  upper  member,  and  the  die  on  its  base.  The  for- 
mer, as  will  be  observed,  is  made  with  a  flanged  circular  base  and  hub  to 
enter  the  seat  bored  in  the  cast  iron  head;  while  the  die  itself  is  secured  by 
four  screws  to  the  lower  member  or  base  proper.  The  punch  is  positioned 
by  two  TVmch  dowels  and  two  j-inch  dowels  are  used  in  the  die.  /  - 

The  stripper  is  of  the  type  which  is  made  of  one  piece  milled  out  to  form 
a  free  passage  for  the  strip  of  stock.  The  stock  stop  is  in  the  form  of  a 
rocker  or  trigger  with  light  spring  to  hold  it  down  normally  with  its  hooked 
inner  end  in  the  path  of  the  stock.  When  the  press  slide  descends  the  con- 
tact screw  A  carried  by  the  punch  head  strikes  the  stop  B  and  causes  the 
inner  end  to  rise  so  that  when  the  slide  and  punch  start  to  ascend  the  stop 
clears  the  strip  of  stock  momentarily  and  permits  it  to  be  fed  forward  to  be 
engaged  again  by  the  stop  which  has  been  released  at  the  instant  the  punch 
has  cleared  the  die. 


28  PUNCHES  AND  DIES 

A  single  T\-inch  by  18-thread  screw  secures  the  punch  in  its  seat,  the 
screw  having  a  countersunk  head  to- come  just  below  the  face  of  the  holder. 
The  die  screws  are  four  in  number  and  are  J  by  20  thread,  fillister  head 
screws.  The  dowels  are  ground  perfectly  straight,  and  once  in  place  there 
is  no  possibility  of  either  punch  or  die  shifting  in  its  seat.  Dimensions  of 
all  such  locating  and  fastening  member  for  different  sizes  of  dies  will  be 
found  in  another  section. 

MATERIALS  USED 

It  is  not  the  intention  in  this  chapter  to  enter  into  a  description  of 
methods  of  making  each  and  every  part  of  the  blanking  dies  covered  by  the 
illustrations.  The  actual  work  of  the  tool  room  with  its  high-grade  hand 
and  machine  processes  will,  however,  be  described  somewhat  in  detail  later 
on,  not  only  in  connection  with  the  making  of  blanking  tools  but  also  in 
reference  to  the  production  of  other  dies  in  their  various  forms. 

In  the  present  chapter  it  is  the  intention  to  set  forth  some  general 
principles  respecting  the  characteristic  forms  of  blanking  tools  and  some 
of  the  points  that  have  to  be  observed  by  the  tool  maker  who  lays  out  and 
makes  up  the  dies.  These  points  include  such  items  as  the  materials  re- 
quired, clearances  in  dies,  allowances  for  stock  in  strippers,  positions  of 
stops,  location  of  die  in  respect  to  the  edges  of  the  base  in  order  to  place 
the  blank,  say,  longitudinally  with  the  stock,  or  square  across  the  strip,  or 
at  some  angle  to  which  its  contour  best  adapts  it.  The  interesting  process 
of  "finding"  the  blank,  that  is  determining  its  exact  outline  and  dimensions 
to  enable  later  operations  to  draw  it  or  form  it  into  a  finished  article  of  the 
required  shape  and  proportions,  constitutes  a  special  subject  of  itself  which 
will  be  developed  accordingly  under  its  own  specific  chapter  head. 

BASES,  HEADS,  AND  PINS 

The  tools  in  Figs.  33,  34,  and  35  have  die  base  and  head  of  cast  iron, 
both  to  standard  dimensions  in  accordance  with  the  sizes  given  in  Chapter 
XV,  at  page  343.  The  pillars,  or  guide  pins,  for  such  tools  are  usually  of  a 
good  grade  of  steel  accurately  ground  to  size,  which  gives  them  a  close 
sliding  fit  in  the  holes  bored  in  the  head.  Where  tools  of  this  form  are 
operated  more  or  less  continuously  on  large  lots  of  work,  it  is  the  practice 
in  some  places  to  bush  the  head  and  harden,  grind,  and  lap  both  guide  pins 
and  bushings,  thus  preserving  the  wearing  surfaces  indefinitely  and  where 
replacement  of  worn  parts  eventually  becomes  necessary,  simplifying  the 
process  appreciably. 

i  Ordinarily,  any  given  set  of  tools  in  the  press  room  has  a  limited  run, 
of  a  few  days  say,  and  then  is  put  aside  until  another  lot  of  similar  work 
comes  along.  The  rapidity  with  which  such  tools  produce  parts  makes 
continuous  operation  with  any  one  set  of  dies  a  rare  event  in  the  general 


BLANKING  DIES 


29 


factory.  Consequently  there  is  relatively  little  wear  on  the  guide  pins  and 
the  corresponding  holes  in  the  head,  and  the  surfaces  will  usually  remain  in 
good  condition  indefinitely. 


fol 


Dowel 


.090 

The  Work 
C.R.  Steel 


Die  Details 
°  Taper  on  a  Side 


FIG.  35.  —  Details  of  wheel  blanking  die 

BLANKING  DIE  CLEARANCE  OR  RELIEF 

It  is  generally  the  practice  in  working  out  a  blanking  die  to  allow  one- 
half  degree  relief  or  taper  on  each  side  as  indicated  by  the  sectional  view 
of  the  die  detail  in  Fig.  35.  This  will  be  sufficient  in  most  cases,  for  slight 
though  the  amount  of  clearance  or  taper  may  be  it  accomplishes  a  number 
of  results.  It  gives,  primarily,  a  gradually  increased  area  of  opening  in  the 
die  to  facilitate  the  passing  through  of  the  blanks  as  cut  out  without  likeli- 
hood of  their  wedging  and  jamming  as  successive  blanks  are  forced  down 


30  PUNCHES  AND  DIES 

upon  them;  it  provides  a  nominal  amount  of  rake  at  least,  at  the  cutting 
edge  of  the  die  and  to  that  degree  aids  in  the  free  cutting  of  the  blank.  At 
the  same  time  the  amount  of  clearance  or  taper  is  so  slight  that  in  most 
cases  the  increase  in  the  size  of  the  blank  as  the  die  is  sharpened  by  grind- 
ing across  the  face  is  negligible,  even  though  the  die  is  reground  many 
times. 

ADVANTAGES  OF  SHAVING  DIES 

As  a  matter  of  fact,  while  the  factors  of  natural  wear  and  the  grinding 
off  of  the  die  face  do  necessarily  result  in  a  little  enlargement  of  the  blank, 
this  is  not  a  serious  matter  of  itself,  for  the  following  reasons:  In  the  first 
place,  if  blanked  parts  are  to  be  held  to  an  absolute  size  or  if  their  edges 
are  required  to  be  perfectly  smooth  and  with  square,  unbroken  corners, 
they  should  be  passed  through  a  shaving  die  in  a  second  operation  where 
they  will  be  brought  to  exact  dimensions,  and  finished  with  clean,  sharp 
edges.  And,  assuming  they  are  to  be  shaved,  the  increase  in  the  blank 
size,  due  to  the  condition  of  the  blanking  dies,  should  make  no  difference, 
for  the  shaving  process  will  restore  the  piece  to  size  even  though  one-  or 
two-thousandths  more  are  to  be  taken  off  than  was  "originally  planned 
for  in  laying  out  the  shaving  tools. 

SHAVING  DIES  ESPECIALLY  SERVICEABLE 

These  shaving  dies  are  especially  useful  when  accurate  work  is  to  be 
maintained  in  the  case  of  blanks  that  are  rather  heavy  or  of  thick  stock  as 
compared  with  their  diameter  or  width.  Here,  with  the  heavier  material, 
it  is  more  difficult  to  secure  accurate,  clean  contours  on  the  blank  and  often 
not  only  one  but  two  shaving  dies  are  used  after  the  work  is  blanked  to 
finish  it  as  required,  the  amount  removed  by  the  secondary  operations 
being  divided  properly  between  the  two  sets  of  shaving  tools. 

In  the  main,  however,  shaving  dies  are  not  extensively  employed  in  the 
average  shop  for  the  reason  that  sufficiently  close  results  for  the  greater 
part  of  press  manufactured  pieces  are  obtainable  without  them.  It  is  also 
the  case  that  where  shaving  dies  could  be  utilized  to  great  advantage  in 
various  ways,  they  are  only  too  often  disregarded  entirely  or  are  perhaps 
too  little  known  in  some  classes  of  shops  to  be  appreciated  at  their  full 
worth.  In  some  other  shops  they  are  commonly  used  for  both  exterior 
finishing  of  blanks  and  for  shaving  pierced  openings  as  well. 

Shaving  tools  of  different  kinds  will  be  found  illustrated  in  detail  in 
Chapters  VI  and  VII. 

TABLE  OF  DIE  CLEARANCES  OR  RELIEF 

It  is  sometimes  of  value  to  know  how  much  increase  in  blanking  die 
size  occurs  as  the  face  is  ground  down  in  resharpening  and  for  this  reason 
Table  1  has  been  worked  out  to  cover  various  angles  of  taper  besides  the 


BLANKING  DIES 


31 


conventional  slope  of  J  degree  on  a  side.  While  the  half  degree  taper  relief 
or  clearance  from  vertical  line  has  been  specified  as  almost  universally  used 
for  the  ordinary  run  of  blanking  dies,  there  are  special  instances  where  this 
angle  has  been  exceeded  appreciably,  and  this  is  especially  true  in  respect 
to  certain  classes  of  piercing  and  perforating  dies. 

While,  ordinarily,  the  angle  of  \  degree  on  a  side  will  allow  of  the  free 
discharge  of  the  slugs  from  perforated  blanks,  such  materials  as  aluminum 
and  similarly  soft  metals  sometimes  produce  slugs  that  in  the  small  sizes, 
particularly,  tend  to  swage  into  the  walls  of  the  piercing  die  when  forced 

TABLE  1 


A 

!/ 

Amount  Ground 
from  Face 

SECTION. 

t 

THROUGH 

DIE 

*|  p      Clearance  =  C 


Amount  ground 

from  face  of  die  in 

thousandths 


Clearance  in  thousandths  corresponding  to  degrees  on  each  side 


In. 

*deg. 

Ideg. 

H  deg. 

2  deg. 

2j  deg. 

0.010 

0.000087 

0.000175 

.  0.000262 

0.000349 

0.000437 

0.020 

0.000175 

0.000350 

0.000524 

0.000698 

0.000873 

0.030 

0.000241 

0.000525 

0.000786 

0  001047 

0.001310 

0.040 

0.000378 

0.000700 

0  001048 

0  001396 

0  001746 

0.050 

0.000437 

0.000875 

0.001310 

0.001745 

0.002183 

0.060 

0.000524 

0.001050 

0.001572 

0.002094 

0.002620 

0.070 

0.000611 

0.001225 

0.001834 

0.002443 

0.003016 

0.080 

0.000698 

0.001400 

0.002096    0.003092 

0.003493 

0.090 

0.000776 

0.001575 

.0.002358 

0.003141 

0.003929 

0.100 

0.000870 

0.001750 

0.002620 

0.003493 

0.004370 

0.110 

0.000960 

0.001925 

0.002882 

0.003839 

0.004803 

0.120 

0.001047 

0.002100 

0.003144 

0.004188 

0.005239 

0.130 

0.001135 

0.002275 

0.003406 

0.004537 

0.005677 

0.140 

0.001222 

0.002450 

0.003668 

0.004886 

0.006112 

0.150 

0.001309 

0.002625 

0.003930 

0.005235 

0.006549 

0.160 

0.001417 

0.002800 

0.004192 

0.005584 

0.006986 

0.170 

0.001484 

0.002975 

0.004554 

0.005933 

0.007422 

0.180 

0.001571 

0.003150 

0.004712 

0.006282 

0.007859 

0.190 

0.001658 

0.003325 

0.004978 

0.006631 

0.008295 

0.200 

0.001746 

0.003500 

0.005240 

0.006980 

0.008732 

0.210 

0.001827 

0.003675 

0.005502 

0.007329 

0.009169 

0.220 

0.001914 

0.003850 

0.005764 

0.007678 

0.009605 

0.230 

0.002001 

0.004025 

0.006026 

0.008027 

0.010042 

0.240 

0.002088 

0.004200 

0.006288 

0.008376 

0.010478 

0.250 

0.002175 

0.004375 

0.006550 

0.008725 

0.010915 

32  PUNCHES  AND  DIES 

down  by  the  punch  and  because  of  the  expanding  action,  due  to  the  pressure 
upon  their  limited  areas,  these  slugs  may  then  stick,  and  stack  up  and,  be- 
coming welded  together,  are  likely  to  cause  the  punch  to  break  or  the  die 
to  become  chipped  around  the  edges  of  the  small  hole.  It  is  often  the  case 
that  such  slugs  emerge  from  the  die  in  all  appearance  like  a  small  solid  rod 
of  material,  built  up  of  thin  disks  or  slugs  pressed  firmly  together. 

The  table  of  various  angles  with  corresponding  diameters  at  different 
points  in  the  thickness  of  the  die  may  therefore  be  of  interest  in  connection 
with  piercing  dies  as  well  as  blanking  tools. 

EXPLANATION  OF  THE  TABLE 

The  table  is  arranged  to  show  the  additional  amount  at  each  side  of  a 
die  for  every  depth  of  ten-thousandths  ground  off  of  its  top  face.  This, 
by  the  way,  is  much  more  than  the  average  amount  removed  in  one  grind- 
ing of  an  ordinary  die,  but  it  is  a  convenient  increment  to  work  from  and 
the  quantities  in  the  columns  that  follow  are  very  readily  modified  to 
correspond  to  any  specified  amount  taken  off  the  die  face  in  the  grinding 
operation. 

Consider  the  half-degree  column :  The  increase  at  each  side  of  the  die  is 
entirely  negligible  when  the  first  0.010  inch  has  been  ground  from  the  face, 
and  only  after  the  die  has  been  ground  down  0.120  inch  or  almost  f  inch 
does  the  diameter  of  the  die  become  0.001  inch  greater  on  each  side  or 
0.002  inch  more  over  all. 

THE  LIFE  OF  A  DIE 

It  is  obvious  from  the  table,  that,  even  with  angles  of  side  clearance 
greater  than  the  common  one  of  J  degree  there  is  little  change  in  the  die 
size  until  a  considerable  amount  has  been  removed  from  its  face. 

Usually  an  enormous  quantity  of  work  can  be  produced  in  a  die  before 
its  over-size  becomes  objectionable;  and  in  case  the  blank  is  to  be  shaved 
subsequently,  there  is  an  even  greater  period  of  service  possible  before  the 
slight  addition  to  the  blank  size  has  to  be  taken  into  consideration. 

With  fairly  small  blanking  dies,  such,  for  example,  as  we  have  been 
considering  for  producing  the  gear  wheels  in  Figs.  33  and  34,  it  is  usually 
unnecessary  to  grind  off  more  than,  say,  0.005  inch  for  each  resharpening 
operation.  Before  grinding  becomes  necessary  at  all,  at  least  30,000  steel 
blanks  will  have  been  produced  and  this  means  that  with  the  same  output 
after  each  grinding,  something  like  1,500,000  blanks  can  be  made  before  the 
die  has  been  reduced  one-quarter  of  an  inch  in  thickness.  And  this  is  only 
a  part  of  the  entire  die  at  that. 

With  lighter  gage  stock  and  softer  material  the  amount  of  work  blanked 
in  such  a  die  between  sharpening  operations  is  greatly  increased . 


BLANKING  DIES 


33 


o 


ANOTHER  FORM  OF  DIE 

This  feature  of  large  quantity  production  between  successive  grindings 
enables  another  form  of  blanking  die  to  be  used  occasionally,  particularly 
on  such  parts  as  toothed  wheels  where  it  may  be  preferred  to  have  the  die 
perfectly  straight  for  a  certain 
distance  up  and  down,  without 
giving  it  side  clearance  in  the 
usual  manner. 

Such  a  die  is  shown  at  A,  Fig. 
36,  and  for  ready  comparison,  the 
usual  die  with  straight  taper  in- 
side of  J  degree  on  a  side  is  shown 
directly  above  at  B,  Fig.  37.  The 
die  A,  it  will  be  seen,  is  formed 
straight  down  from  the  top  for  a 
depth  of  J  inch  and  below  that 
has  the  usual  angle  at  the  side. 
The  straight  upper  portion,  how- 
ever, should  in  accordance  with 
the  figures  given  above,  produce 
a  million  and  a  half  pieces  before 
it  has  been  ground  to  the  point 
where  the  tapered  portion  begins, 
and  it  thus  gives  the  advantage 
of  a  construction  where  no  change 
occurs  in  the  size  of  the  blanks 
(except  for  the  unappreciable 
amount  of  wear  in  the  die  itself) 
until  the  actual  depth  is  reached 
in  grinding  where  the  half  degree 
taper  commences. 

It  is  quite  apparent  that, 
eliminating  possibility  of  acci- 
dents, such  a  set  of  dies  would  be 
apt  to  answer  for  any  but  exceed- 


FIG.  37 


FIG.  36 
Two  methods  of  relieving  dies 


ingly  long  runs  of  work,  and  in  most  cases  would  not  require  replacement 
"before  some  modification  in  the  work  itself  would  render  necessary  a  new 
pet  of  dies  throughout. 

CLEARANCE  BETWEEN  PUNCH  AND  DIE 

Theoretically  a  blanking  punch  is  not  supposed  to  enter  the  die  opening 
when  in  operation  but  to  stop  at  the  end  of  the  down  stroke  of  the  press 


34  PUNCHES  AND  DIES 

slide  with  its  lower  end  practically  flush  with  the  face  of  the  die.  There  is 
a  definite  percentage  of  clearance  between  the  punch  and  the  die,  the  punch 
being  smaller  by  an  amount  dependent  upon  the  thickness  of  the  stock  and 
the  character  of  the  material,  whether  hard,  soft,  etc.  On  very  small  work 
and  where  very  thin  metal  is  blanked,  the  punch  is  nominally  the  size 
of  the  die.  But  with  heavier  stock  the  clearance  between  punch  and  die 
becomes  an  appreciable  quantity. 

For  any  given  kind  of  sheet  metal  the  amount  of  clearance  allowed  be- 
tween punch  and  die  is  based  upon  the  thickness  of  the  metal  and  varies 
directly  with  the  gage  of  the  stock.  Considered  in  respect  to  different 
classes  of  material,  the  clearance  is  greater  for  hard  rolled  steel  than  for 
soft  steel  and  brass.  For  very  large  dies  there  is  a  greater  percentage 
allowed  for  clearance  than  for  small  dies,  but  for  the  general  run  of  sizes 
there  is  close  uniformity  for  any  specific  grade  of  work. 

There  must  not  be  excessive  clearance  in  any  case  for  this  may  result 
in  slight  curling  up,  or  bending  of  the  edge  along  the  blank,  and  prevent  a 
smooth  even  cut  from  being  produced.  Table  2  has  been  computed  to 
cover  clearances  for  all  gages  of  material  in  the  three  gage  standards  com- 
monly used  for  sheet  metal. 

[  TABLE  OF  CLEARANCES  BETWEEN  PUNCH  AND  DIE 

This  table  has  been  worked  out  to  give  clearances  based  upon  various 
percentages  of  stock  thickness  ranging  from  5  per  cent  to  12  per  cent. 
The  first  column  is  arranged  to  advance  by  increments  of  0.005  inch,  and 
directly  opposite,  under  the  respective  gage  headings,  are  grouped  the 
actual  gage  equivalents  most  closely  corresponding  to  the  thickness  in  the 
first  column. 

Of  the  six  columns  of  clearances,  the  first  three  are  particularly  adapted 
to  very  accurate  work  and  small  parts  especially,  5  per  cent  being  the 
allowance  computed  for  Brass  and  Soft  Steel;  6  per  cent  for  Medium 
Rolled  Steel;  and  7  per  cent  for  Hard  Rolled  Steel.  Similarly,  the  other 
three  columns  cover  the  general  run  of  work  where  a  little  more  clearance 
is  permissible,  8  per  cent  being  here  allowed  for  Brass  and  Soft  Steel;  10 
per  cent  for  Medium  Rolled  Steel;  and  12  per  cent  for  Hard  Rolled  Steel. 

These  clearances  apply  to  piercing  dies  as  well  as  to  dies  for  blanking. 
In  blanking,  the  die,  of  course,  determines  the  size  of  the  piece,  and  here  the 
allowance  between  punch  and  die  must  be  made  in  the  punch,  the  die  being 
made  to  the  size  required  for  the  work,  and  the  punch  an  amount  smaller 
according  to  the  allowances  in  the  table.  If  the  work  is  to  be  shaved  after 
blanking,  the  allowance  for  shaving  is  necessarily  added  to  the  size  of  the 
blanking  die  and  the  punch  is  also  made  larger  by  a  corresponding  amount. 

In  reference  to  the  sizing  of  work  accurately  in  the  blanking  die,  it  may 
be  pointed  out  here  that  while  it  is  the  generally  accepted  practice  to  make 


BLANKING   DIES 

TABLE  2 


35 


Gage 

Clearance  between  blanking  punch  and  die 
based  upon  percentage  of  stock  thickness 

American  or 

U.  S.  Standard 

Birmingham 

Brown  &  Sharpe 

for  plate 

or  Stubba 

No. 

Thick- 
ness 

No. 

Thick- 
ness 

No. 

Thick- 
ness 

5% 

6% 

7% 

8% 

10% 

12% 

40 

0.003144 

39 

0.003531 

0.005 

38 

0.003965 

0.00025 

0.0003 

0.0003 

0.0004 

0.0005 

0.0006 

37 

0.004453 

36 

0.005 

35 

0.005614 

38 

0.00625 

36 

0.004 

34 

0.006304 

37 

0.006640 

35 

0.005 

33 

0.00708 

36 

0.007031 

34 

0.007 

0.010 

32 

0.00795 

35 

0.007812 

33 

0.008 

0.0005 

0.0006 

0.0007 

0.0008 

0.001 

0.0012 

31 

0.008928 

34 

0.008593 

32 

0.009 

30 

0.010025 

33 

0.009375 

31 

0.010 

29 

0.011257 

32 

0.010156 

30 

0.012 

31 

0.010937 

0.015 

28 

0.012641 

29 

0.013 

0.00075 

0.0009 

0.00105 

0.0012 

0.0075 

0.0018 

27 

0.014195 

30 

0.0125 

28 

0.014 

29 

0.014062 

26 

0.01594 

28 

0  015625 

27 

0.016 

0.020 

25 

0.0179 

27 

0.017187 

26 

0.018 

0.0010 

0.0012 

0.0014 

0  0016 

0.002 

0.0024 

26 

0.01875 

25 

0.020 

24 

0.0201 

25 

0.021875 

24 

0.022 

' 

0.025 

23 

0.022571 

24 

0.025 

23 

0.025 

0.00125 

0.0015 

0.00175 

0.0020 

0.0025 

0.0030 

22 

0  025347 

23 

0.028125 

22 

0.028 

0.030       21 

0  028462 

0.00150 

0.0018 

0.0021 

0.0024 

0.0030 

0.0036 

20 

0.031961 

22 

0.03125 

21 

0.032 

0.035       19 

0.03589^ 

21 

0.034375 

20 

0.035 

0.00175 

0.0021 

0.00245 

0.0028 

0.0035 

0.0042 

0.040       18 

0.040303 

20 

0.0375 

19 

0.042 

0.002 

0.0024 

0.0028 

0.0032 

0.004 

0.0048 

0-045       17 

0.045257 

19 

0.04375 

0.00225 

0.0027 

0.00315 

0.0036 

0.0045 

0  0054 

0.050       16 

0.05082 

18 

0.050 

18 

0.049 

0.0025 

0.0030 

0.0035 

0.0040 

0.0050 

0  0060 

0055       15 

0  057068 

17 

0.0562 

0.00275 

0.0033 

0.00385 

0.0044 

0.0055 

0  0066 

0.060 

17 

0.058 

0.003 

0.0036 

0.0042 

0.0048 

0.006 

0.0072 

0065       14 

0.064084 

16 

0.0625 

16 

0.065 

0.00325 

0.0039 

0.00455 

0.0052 

0.0065 

0.0078 

0.070       13 

0.071961 

15 

0  070312 

15 

0.072 

0.0035 

0.0042 

0.0049 

0.0056 

0007 

0.0084 

0  075 

0.00375 

0.0045 

0.00525 

0.0060 

0.0075 

00090 

0.080 

12 

0  080808 

14 

0.078125 

0.004 

0.0048 

0.0056 

0.0064 

0.008 

0  0096 

0  085 

14 

0.083 

0.00425 

0.0051 

0.00595 

0.0068 

0.0085 

00102 

0.090 

11 

0  090742 

0.0045 

0.0054 

0.0063 

0.0072 

0.009 

0.0108 

0.095 

13 

0.09375 

13 

0  095 

0.00475 

0.0057 

0.00665 

0.0076 

0.0095 

0  0114 

0.100 

10 

0.10189 

0.005 

0.0060 

0.007 

0.0080 

0.010 

0.0120 

0  105 

0.00525 

0.0063 

0.00735 

0.0084 

0.0105 

0.0126 

0-110 

12 

0.109375 

12 

0.109 

0.00550 

0.0066 

0.00770 

0.0088 

0.011 

0.0132 

0  115 

9 

0.11443 

0.00575 

0.0069 

0.00805 

0.0092 

0.0115 

0.0138 

0  120 

11 

0.120 

0.006 

0.0072 

0.00840 

0.0096 

0.072 

0.0144 

0.125 

11 

0.125 

0.00625 

0.0075 

0.00875 

0.0100 

0.0125 

0.0150 

0.130 

8 

0.12849 

0.00650 

0.0078 

0.00910 

0.0104 

0.013 

0.0156 

0.135 

10 

0.134 

O.OQ675 

0.0081 

0.00945 

0.0108 

0.0135 

0.0162 

0.140 

10 

0.140625 

0.007 

0.0084 

0.00980 

0.0112 

0.014 

0.0168 

0.145         7 

0.14428 

0.00725 

0.0087 

0.01015 

0.0116 

0.0145 

0.0174 

0.150 

•9 

0.148 

0.0075 

0.009 

0.01050 

0.0120 

0.015 

0.0180 

0.155 

0.00775 

0.0093 

0.01085 

0.0124 

0.0155 

0.0186 

0-160 

6 

0.16202 

9 

0.15625 

0.008 

0.0096 

0.01120 

0.0128 

0.016 

0.0192 

0.165 

8 

0.165 

0.00825 

0.0099 

0.01155 

0.0132 

0.0165 

0.0198 

0  170 

8 

0.171875 

0.00850 

0.0102 

0.01190 

0.0136 

0.017 

0.0204 

0.175 

0.00875 

0.0105 

0.01225 

0.0140 

0.0175 

0.0210 

0.180 

7 

0.180 

0.009 

0.0108 

0.01260 

0.0144 

0.018 

0.0216 

0.185 

5 

0.18194 

0.00925 

0.0111 

0.01295 

0.0148 

0.0185 

0.0222 

0.190 

7 

0.1875 

0.00950 

0.0114 

0.01330 

0.0152 

0.019 

0.0228 

0.195 

0.00975 

0.0117 

0.01365 

0.0156 

0.0195 

0.0234 

0.200 

0.0100 

0.0120 

0.01400 

0.0160 

0.020 

0.0240 

0.205 

4 

0.20431 

6 

0.203125 

6 

0.203 

0.01025 

0.0123 

0.01435 

0.0164 

0.0205 

0  0246 

0.210 

0.01050 

0.0126 

0.01470 

0.0168 

0.021 

0.0252 

0.215 

0.01075 

0.0129 

0.01505 

0.0172 

0.0215 

0.0258 

0.220 

5 

0.21875 

5 

0.220 

0.0110 

0.0132 

0.01540 

0.0176 

0.022 

0.0264 

0.225 

0.01125 

0.0135 

0.01575 

0.0180 

0.0225 

0.0270 

0.230 

3 

0.22942 

0.01150 

0.0138 

0.01610 

0.0184 

0.023 

0.0276 

0.235 

4 

0.234375 

0.01175 

0.0141 

0.01645 

0.0188 

0.0235 

0.0282 

0.240 

4 

0.238 

0.01200 

0.0144 

0.01680 

0.0192 

0.024 

0.0288 

0.245 

0.01225 

0.0147 

0.01715 

0.0196 

0.0245 

0.0294 

0.250 

2 

0.25763 

3 

0.250 

3 

0.259 

0.01250 

0.0150 

0.01750 

0.0200 

0.025 

0.0300 

36  PUNCHES  AND  DIES 

the  die  to  the  exact  dimensions  required  for  the  blanked  piece,  some 
authorities  recommend  making  the  die  undersize  by  two-thousandths  of  an 
inch,  allowing  clearance  on  the  punch  as  usual  and  shearing  the  die.  The 
shear  on  the  die  gives  a  freer  blanking  action  tending  to  greater  accuracy 
in  the  work  and  at  the  same  time  it  lengthens  the  cutting  opening  in  the  die 
in  direct  proportion  to  the  degree  of  shear  given  the  die  face. 

Thus  if  a  die  is,  say,  two  inches  long  across  the  opening  and  it  is  given 
^V  inch  shear,  or  say  2  degrees,  the  actual  distance,  as  now  measured  across 
the  die  opening  to  which  the  work  will  be  blanked,  is  nearly  0.002  inch  more 
than  when  the  die  face  was  parallel  with  the  punch.  This  is  compensated 
for  by  making  the  minus  allowance  of  0.002  inch  as  given  above. 

Also,  with  flat  dies,  where  the  stock  is  of  heavy  gage,  there  is  a  slight 
tendency  for  the  blank  to  compress  and  the  die  to  open  by  a  very  small 
amount,  so  some  tool  rooms  adopt  the  practice  of  making  the  die  a  slight 
amount  under  size  to  offset  this  tendency. 

PRESSURES  REQUIRED  FOR  BLANKING 

The  action  of  blanking  tools  is  to  shear  the  metal  by  cutting  the  blank 
through  the  stock,  and  knowing  the  shearing  strength  of  a  given  grade  of 
material  it  is  possible  to  make  up  a  table  that  will  show  approximate 
pressures  necessary  to  blank  a  certain  size  piece.  These  pressures  repre- 
sented in  pounds  are  necessarily  approximate  only,  for  various  factors 
entering  into  each  case  modify  the  theoretical  values  from  which  the  table 
is  compiled.  Such  factors  are  the  condition  of  punch  and  die  at  the  time; 
the  degree  of  clearance;  the  general  outline  of  the  work  whether  plain  edged 
or  complicated  by  various  projections;  the  character  of  the  cutting  faces 
of  punch  and  die,  whether  flat  or  sheared,  and,  if  the  latter,  the  degree  and 
nature  of  the  shear,  etc. 

Table  3  is  based  upon  a  unit  length  of  shear  of  1  inch  with  approximate 
pressuresvin  pounds  for  different  thicknesses  of  metal  with  one  inch  length 
of  cut.  Where  the  outline  of  the  work  is  2,  3,  6,  8  inches  long  or  any  other 
length,  the  corresponding  pressure  necessary  is  found  by  simply  multiply- 
ing the  quantity  in  the  table  opposite  the  thickness  of  stock  by  the  actual 
distance  around  the  piece. 

This  table  has  been  computed  for  gages  in  the  U.  S.  Standard  Plate 
system  only,  but  the  thicknesses  under  these  gage  numbers  correspond 
closely  with  other  numbers  in  the  American  or  B.  &  S.  gage  and  the  Bir- 
mingham gage  so  that  by  finding  the  nearest  thickness  in  the  table  the 
corresponding  pressures  for  the  other  gages  mentioned  are  easily  located 
in  the  table.  A  similar  table  for  piercing  dies,  but  based  upon  a  one-inch 
diameter  of  hole,  will  be  found  in  the  Chapter  on  Piercing  Tools. 


BLANKING  DIES 


37 


TABLE  3.  —  APPROXIMATE  PRESSURE  IN  LBS.  FOR  SHEARING  BRASS  AND  STEEL  FOR 

1-iNCH  LENGTH  OF  Cur 

Shearing  strength  of  brass  per  sq .  in.  =  35,000  Ibs. 

Shearing  strength  of  steel  per  sq.  in.  =  50,000  Ibs. 

Shearing  strength  of  high-carbon  steel  per  sq.  in.  =  75,000  Ibs. 


Gage,  U. 

S.  Standard  plate 

Lbs.  pressure 

No 

Thickness 

Brass 

Steel 

High  -carbon  steel 

28 

0.015625 

546 

780 

1,170 

27 

0.0171875 

595 

850 

1,275 

26 

0.01875 

615 

940 

1,400 

25 

0  021875 

770 

1,090 

1,635 

24 

0.025 

875 

1,250 

1,875 

23 

0.028125 

980 

1,405 

2,100 

22 

0.03125 

1085 

1,560 

2,340 

21 

0.034375 

1190 

1,715 

2,550 

20 

0.0375 

1312 

1,875 

2,812 

19 

0.04375 

1540 

2,185 

3,280 

18 

0.05 

1750 

2,500 

3,750 

17 

0.05625 

1960 

2,810 

4,200 

16 

0.0625 

2187 

3,125 

4,687 

15 

0.0703125 

2480 

3,515 

5,250 

14 

0.078125 

2710 

3,905 

5,850 

13 

0.09375 

3290 

4,700 

7,050 

12 

0.109375 

3815 

5,465 

8,200 

11 

0.125 

4375 

6,250 

9,375 

10 

0.140625 

4935 

7,030 

10,500 

9 

0.15625 

5460 

7,810 

11,700 

8 

0.171875 

6020 

8,598 

12,900 

i-r 
i 

0.1875 

6562 

9,375 

14,062 

6 

0.203125 

7075 

10,155 

15,225 

5 

0.21875 

7667 

10,935 

16,425 

4 

0.234375 

8190 

11,715 

17,550 

3 

0.250 

8750 

12,500 

18,750 

2 

1 

Rule:  Multiply  thickness  of  stock  by  length  by  shearing  strength  of  material 

THE  EFFECT  OF  SHEARED  TOOLS 

Where  the  tools  are  sheared,  that  is  beveled  off  from  one  side  to  the 
other  to  give  a  gradual  sloping  cutting  action,  the  pressure  required  is  much 
less  than  given  in  the  table,  and  may  usually  be  taken  at  one-half  of  the 
pressures  for  flat  tools  for  stock  not  over,  say,  J-inch  thick.  Beyond  that  a 
safer  amount  would  be  two-thirds  of  the  pressure  necessary  for  dies  with- 
out shear. 


38 


PUNCHES  AND   DIES 


The  action  of  the  sheared  face  punch  has  been  referred  to  in  connection 
with  Fig.  7  in  Chapter  I.  Blanking  punches  of  considerable  length  of  cut 
are  often  finished  along  the  face  at  an  angle  as  indicated  in  Fig.  38  to  pro- 
vide the  easy  cutting  action  desired.  And  sometimes  for  the  same  purpose 
the  face  of  the  die  itself  is  finished  at  an  angle  and  the  punch  left  square 
on  the  cutting  edge. 


Sheared  Punch 


i  Angle  of 
^   Shear 


Face  of  Die 


FIG.  38.  —  A  sheared  punch 

POSITION  OF  BLANK  OPENING  IN  THE  DIE 

Reference  has  been  made  at  an  earlier  point  in  this  chapter  to  the  loca- 
tion of  blanking  die  openings  in  relation  to  the  edge  of  the  die.  Or,  it 
might  be  better  to  say,  in  respect  to  the  longitudinal,  center  line  of  the 
die. 

The  shape  and  size  of  the  blank  are  the  determining  factors  by  which 
the  location  of  the  die  opening  is  fixed.  If  the  blank  is  a  simple  straight 
piece  and  not  unduly  long,  it  may  be  located  squarely  in  the  die  either 
lengthwise  or  crosswise  according  to  the  width  of  stock  it  may  be  desired 
to  use,  or  to  which  arrangement  will  be  most  advantageous  when  the  feeding 
of  the  stock  and  the  operation  of  the  stock  stop  are  taken  into  consideration. 

It  is  very  often  the  case  that  the  blank  is  of  irregular  form  and  of  such 
outline  that  if  placed  directly  lengthwise  or  crosswise  of  the  die  it  would 
result  in  a  great  waste  of  material,  owing  to  the  area  of  metal  that  would 
lie  between  portions  of  the  blanked  openings  in  the  strip  as  it  was  fed 
through.  In  such  cases  it  is  usually  possible  to  locate  the  die  opening  at 
such  an  angle  as  to  allow  projections  to  overlap  one  another  or  to  nest  in  to- 
gether in  such  manner  as  to  eliminate  to  a  great  extent  the  waste  of  ma- 
terial that  would  otherwise  occur.  Or,  where  this  is  not  feasible  the  same 
economy  in  stock  is  effected  by  so  arranging  the  dies  and  selecting  the 
width  of  strip  material  as  to  allow  the  stock  to  be  fed  through  once  to  allow 
the  blanks  to  be  produced  from  one  side  of  the  strip  and  then  turning  it 
over  for  a  second  passage  through  the  dies  in  which  another  row  of  blanks 


BLANKING  DIES 


39 


are  cut  out  with  their  contours  interlocking  closely  with  the  blanked  open- 
ings formed  in  the  first  passage  of  the  strip  through  the  machine. 

Besides  the  actual  economy  in  material  that  is  brought  about  by 
judicious  arrangement  of  the  dies  relative  to  the  center  line  or  line  of  stock 
feed,  it  is  generally  possible  to  keep  down  to  a  reasonable  number  the  dif- 
ferent widths  of  strip  stock 


carried  in  the  press  room 

rack,  by  so  laying  out  new 

dies   as   to   make   use   of 

some    standard    material 

always   carried  on   hand. 

This    oftentimes    means 

that   the  punch   and   die 

will   be  made  with   their 

center   lines   at  an  angle 

greater  or   less  with   the 

body  of  the  die  so  that  the  work  will  be  blanked  out  obliquely  to  the  edge 

of  the  strip  of  metal. 


oooono! 

B 

FIG.  39.  —  Two  methods  of  locating  blanks  in  the  stock 


FIG.  40.  —  Die  for  a  slender  blank 
SOME  EXAMPLES 

It  is  apparent  that  even  with  simple  forms  of  blanks  such,  for  example, 
as  small  gears  or  plain  disks,  there  is  an  important  saving  in  material  by 
selecting  stock  of  sufficient  width  to  permit  two  or  more  rows  of  blanks  to 
be  made  from  the  same  .strip.  Thus  taking  the  illustration  in  Fig.  39 
which  shows  a  strip  of  stock  from  which  i£-inch  disks  are  blanked  in  a 


40 


PUNCHES  AND   DIES 


single  row  as  at  A,  and  a  wider  strip  for  two  rows  at  B.    By  locating  the 
blanks  in  staggered  position  the  wider  strip  enables  two  rows  to  be  produced 

in  a  width  J-inch  narrower  than  the  com- 
bined width  of  two  single  strips  like  the 
narrow  one  at  A.  And  a  still  wider  strip 
for  three  rows  of  blanks  would  be  even 
more  effective  from  the  point  of  view  of 
stock  economy. 

Some  illustrations  of  blanking  dies  with 
the  work  done  in  various  positions  in  respect 
to  the  center  line  of  the  die  are  shown  in  the  views  that  follow:  In  Fig.  40,  for 


FIG.  42.  —  A  yocker  arm  blanking  die 

example,  is  a  set  of  blanking  tools  for  making  a  long  slender  bar,  Fig.  41,  car- 
rying a  clover  leaf  form  of  head, 
the  piece  measuring  about   2J 
inches  long  over  all  and  the  body        M  I 
being  only  ^Vinch  wide.  The  die    l'^c 
opening  is  parallel  to  the  center 
and  the  stock  stop  is  seated  in  the 
stripper  at  an  angle  to  clear  the 
fillister  head  screw  at  the  side. 

The  blanking  die  for  the  piece  in  Figs.  42  and  43  is  made  to  cut  out  the 
work  at  right  angles  to  the  length  of  stock  or  90  degrees  around  from  the 
position  of  the  die  opening  irtvFig.  40.  The  dies  in  Fig.  44  are  also  made  to 
blank  the  work,  Fig.  45,  crosswise  of  the  stock  and  here  is  another  good 


R3,  H.Hard 


Stock 


FIG.  43.  —  Rocker  arm  blank 


BLANKING  DIES 


41 


FIG.  44,  —  Blanking  dies  for  a  thick  piece 


71.290^ 

.145  H.Hard  Stock 
Fig.  45.  —  A  three  lobe  blank 


FIG.  46.  —  Details  of  dies  for  blank  FIG.  47.  —  Blanking  in  double  run  through 

in  Fig.  45  the  press 


42 


PUNCHES  AND  DIES 


illustration  of  the  advantages  in  using  wider  stock  than  necessary  for  a 
single  row  of  blanks  and  then  reversing  the  strip  of  metal  and  running  it 
through  for  the  blanking  out  of  a  second  row  of  parts.  The  construction 
of  this  set  of  blanking  tools  is  shown  in  Fig.  46. 


FIG.  48.  —  Dies  made  with  diagonally  placed  opening 

RELATIVE  POSITIONS  OF  BLANKS 

The  sketch,  Fig.  47,  shows  the  manner  in  which  the  blanks  in  the  first 
row,  1,  1,  1,  are  spaced,  and  how  the  second  series  indicated  by  numerals, 
2,  2,  2,  come  midway  of  the  openings  from  the  first  operation  when  the  stock 


FIG.  49.  —  Another  form  of  blank     FIG.  50.  —  Work  blank  at  an  angle  to  edge  of  stock 

is  fed  through  on  its  second  round.  It  may  be  noticed  incidentally  that 
these  blanks  are  from  what  may  be  considered  quite  heavy  gage  stock  for 
the  small  over-all  dimension. 

Here  again  the  stock  stop  is  located  in  an  angular  position  to  enable 
the  contact  end  to  be  placed  at  the  required  point  and  the  body  to  clear 
the  screws  and  dowels  in  the  die. 

This  die  has  an  extension  stock  guide  and  support  at  the  right  which 


BLANKING  DIES  43 

is  especially  useful  when  feeding  a  strip  through  that  has  already  been 
punched  out  for  one  row  of  blanks. 

Another  die,  with  oblique  position  of  opening  to  blank  the  work  at  an 
angle  to  the  edge  of  the  stock,  is  seen  in  Fig.  48,  the  blank  in  Fig.  49  and 
the  manner  in  which  the  blanks  are  spaced  in  Fig.  50.  Here  is  a  case 
where  the  die  and  punch  are  made  at  an  angle  to  blank  th^  work  along 
closely  parallel  lines  with  a  minimum  of  waste  between  successive  blanks. 
The  stock  required  for  blanks  thrown  around  in  this  way  is  also  much  less 
in  width  than  would  otherwise  be  necessary. 


FIG.  51.  —  An  open  blanking  set 

The  open  blanking  dies  in  Fig.  51  are  likewise  made  to  produce  the  work 
at  a  decided  angle  to  the  line  of  stock  feed,  for  reasons  similar  to  those 
already  explained.  This  blank  is  semi-circular,  2 J-inch  in  diameter,  and 
J-inch  across  the  hole. 

The  line  drawings,  Figs.  52  to  64  inclusive,  show  further  illustrations  of 
strips  of  stock  from  which  various  shapes  of  blanks  of  different  sizes  have 
been  punched.  In  a  number  of  cases  these  blanks  will  be  seen  to  have 
been  made  by  running  the  stock  through  twice,  and  in  these  instances  the 
blank  positions  for  the  first  run  are  indicated  by  the  numeral  1  and  those 
of  the  second  run  are  marked  2. 

The  illustration  in  Fig.  52  shows  the  placing  of  the  blanks  as  produced 
by  the  dies,  Fig.  40. 

,  In  all  cases  referred  to  a  few  dimensions  are  given  approximately  to 
convey  an  idea  of  the  general  proportions  of  the  work. 

These  views  are  presented  as  of  value  in  suggesting  different  ways  in 
which  such  work  may  be  blanked  out  of  the  stock  to  advantage. 

A  number  of  the  dies  thus  far  illustrated  will  be  recognized  as  the  tools 
used  in  blanking  various  pieces  shown  in  the  group  in  Fig.  29,  which  are  a 
few  parts  for  the  Marchant  Calculating  Machine. 


ife^^/S^^ffi 


FIG.  52 


T..^..^ 


FIG.  58 


FIG.  59 
FIGS    52-59.  —  Various  methods  of  locating  blanks  in  stock 


.Vie  FIG.  60 


FlG.  61   ( Interlocking  )  2  Rows 


FIG.  64 


FIG. 


FIGS.  60-64.  —  Methods  of  locating  blanks 


page  44 


BLANKING  DIES 


45 


AMOUNT  OF  STOCK  BETWEEN  ADJACENT  BLANKS 

The  amount  of  metal  to  leave  between  adjacent  blanks  in  the  strip  of 
material  is  dependent  in  a  measure  updti  the  thickness  of  the  stock  and 
also  upon  the  size  and  form  of  the  blank.  As  a  rule  a  minimum  of  ^  inch 
is  considered  good  practice  for  metal  up  to  j^-inch  thick.  From  that 
thickness  on  up  to  J  inch  it  is  preferable  to  leave  from  5\  to  £  inch. 

There  are  cases  where  thin  metal  has  been  blanked  with  considerably 
less  stock  wasted  between  blanks  than  the  TB  inch  referred  to.  But  with 
many  shapes  of  dies  and  with  certain  conditions  of  cutting  edges  there  is 
always  a  possibility  that  the  narrow  bar  of  metal  at  the  ends  or  sides  of  the 
blank  may  "draw"  or  pull  into  the  die  and  result  in  unsatisfactory  opera- 
tion all  the  way  round. 


FIG.  65.  —  Double  blanking  tools 

Moreover,  the  position  and  shape  of  stop  used  is  sometimes  a  factor  in 
fixing  the  allowance  of  stock  between  blanks  at  a  reasonable  amount  that 
will  not  become  distorted  and  unsatisfactory  if  used  as  a  gage  point  for 
feeding  against  the  stop. 

GANG  TOOLS 

Blanking  tools,  like  piercing  dies,  are  often  made  up  two,  three  or  more 
in  a  gang  to  blank  out  as  many  pieces  simultaneously. 

A  simple  blanking  set  of  this  character  is  shown  by  Fig.  65  herewith. 
This  is  an  open  type  of  die  with  provision  for  producing  two  blanks  at 
once.  The  work  is  a  thin  metal  shim  about  3J  inches  long.  It  is  made 
in  large  quantities -and  the  duplex  type  of  die  is,  therefore,  an  aid  to  rapid 
production. 

The  die  is  made  in  a  solid  piece  worked  out  in  the  usual  fashion;  the 
punches  are  made  separately  and  are  secured  to  the  punch  holder  by  screws 


46  PUNCHES  AND   DIES 

and  dowels  in  the  manner  indicated.  The  spacing  between  the  two  dies  is 
sufficient  to  leave  a  strong  wall  of  metal  and  there  is  enough  stock  left 
between  each  pair  of  openings  formed  in  the  strip  of  metal  as  fed  through 
so  that  it  is  again  passed  through  the  dies  for  blanking  out  a  second  lot  of 
shims  between  the  gaps  left  by  the  first  blanking  run. 


,FlG.  66.  —  Blanking  dies  with  pressure  pad  and  stripper 


i 


FIG.  67.  —  Another  blanking  die  with  combined  pressure  pad  and  close  fitting  stripper 

Two  OTHER  BLANKING  DIES  FOE  THIN  WORK 

Two  sets  of  tools  for  parts  somewhat  similar  to  the  work  in  Fig.  65  are 
shown  in  Figs.  66  and  67,  these  being  made  for  blanking  two  pieces  that  are 
very  much  alike.  The  two  dies  are,  however,  directly  opposite  one  another 
in  arrangement.  Each  has  its  advantages.  Both  sets  of  tools  blank  out 
work  three  or  four  inches  long  on  a  side  by  f  to  1  inch  wide  and  only  0.003 
or  0.004  inch  thick.  In  some  cases  the  material  is  brass'  and  in  any  event 
the  stock  is  so  thin  in  proportion  to  its  area  that  special  provision  is  neces- 
sary in  the  tools  to  produce  blanks  that  will  not  be  wrinkled  on  the  surface 
or  torn  and  rough  along  the  edges. 


BLANKING  DIES 


47 


Now  we  have  in  connection  with  drawing  dies  a  feature  known  as  a 
pressure  pad  whose  purpose  is  the  holding  of  the  sheet  metal  under  a  definite 
degree  of  pressure  while  the  operation  of  drawing  is  going  on.  This  is  to 
prevent  wrinkling  of  the  work  and  has  the  effect  of  ironing  out  the  sheet 
metal  as  it  is  drawn  down  into  the  die  from  between  the  pressure  pad  and 
the  upper  face  of  the  die. 

COMBINED  PAD  AND  STRIPPER 

A  similar  pressure  pad  may  be  employed  to  advantage  in  the  construc- 
tion of  blanking  dies  like  those  in  Figs.  66  and  67,  only  in  these  instances 
the  pressure  pad  also  combines  with  it  the  features  of  a  close-fitting  stripper, 
to  clear  the  scrap  from  the  punch. 


1 

\ 

! 

1 

1 

^ 

*_ll_f                                          t_ii_r 

Punch 

^Pressure  Pad  and  Strippe 

r 

} 

Die 

I       I 


FIG.  68.  —  Construction  of  dies  in  Fig.  66 

-Pf 


FIG.  69.  —  Construction  of  dies  in  Fig.  67 

Both  dies  shown  are  of  the  sub-pressed  or  pillar  type  and  the  essential 
features  of  each  are  shown  in  Figs.  68  and  69,  respectively. 

Considering  first  the  tools  in  Figs.  66  and  68,  it  may  be  stated  that  the 
stripper,  instead  of  being  carried  by  the  die  in  the  customary  fashion  for 
blanking  operations,  is  here  a  part  of  the  punch  equipment,  and  mounted 
in  the  manner  shown,  it  is  held  down  by  a  series  of  stiff  springs  which,  when 
the  press  slide  descends,  presses  the  thin  sheet  stock  firmly  against  the 


48  PUNCHES  AND  DIES 

upper  face  of  the  die  and  holds  it  against  possibility  of  movement  while 
the  punch  cuts  out  the  blank.  Upon  the  upstroke,  tjie  pressure  pad  acts 
as  a  close  fitting  stripper,  which  prevents  the  stock  from  lifting  with  the 
punch  and  keeps  it  well  flattened  out  until  the  end  of  the  punch  is  clear  of 
the  work. 

THE  INVERTED  TYPE  OF  DIE 

Referring  now  to  the  other  construction,  Figs.  67  and  69,  it  will  be 
seen  that  the  die  is  inverted  and  carried  as  the  upper  member  of  the  set 
while  the  punch  occupies  the  position  below,  usually  the  place  of  the  die. 

Here  again  the  combined  pressure  pad  and  close-fitting  stripper  are 
carried  by  the  punch  with  a  set  of  heavy  springs  beneath  to  keep  the  face 
of  the  pad  against  the  lower  face  of  the  die  when  the  latter  is  carried  down- 
ward by  the  press  slide.  As  the  die  cuts  out  the  blank  by  forcing  the  stock 
down  over  the  inverted  punch,  the  pressure  pad  maintains  a  firm  degree  of 
pressure  upon  the  stock  and  allows  the  thin  blank  to  be  produced  without 
wrinkling  or  distortion. 

»  j  Upon  the  return  stroke  of  the  press  slide,  the  pressure  pad  acting  now 
as  a  close-fitting  stripper  lifts  the  strip  of  stock  to  the  top  of  the  punch  and 
the  knock-out  carried  in  the  die  above  ejects  the  thin  blank  from  the  die. 

RELATIVE  ADVANTAGES 

There  are  advantages  connected  with  each  arrangement  of  blanking 
tools  for  thin  work  of  the  character  described.  The  construction  in  Figs. 
66  and  68  is  the  more  common,  for  it  is  somewhat  simpler  and  less  expensive 
to  make.  It  has  the  disadvantage  for  very  thin  stock  that  the  blanks  as 
forced  down  through  the  die  openings  may  become  clogged  and  more  or 
less  distorted  in  their  passage  out  of  the  press.  Sometimes,  however,  this 
type  of  die  is  fitted  with  an  ejector  or  knock-out  that  lifts  the  blank  back 
into  the  strip  of  metal,  where  it  is  carried  out  of  the  press  by  the  advancing 
movement  of  the  stock  through  the  dies. 

With  the  inverted  form  of  construction  shown  in  Figs.  67  and  69,  both 
stock  and  blank  are  kept  straightened  out  at  all  times,  there  is  no  oppor- 
tunity for  the  blank  to  become  injured  in  the  dies  as  it  is  ejected  back  onto 
the  strip  by  the  action  of  the  knock-out  above,  and  the  edges  of  both  punch 
and  die  are  kept  clear  of  chips  or  fine  particles  of  metal  by  the  operation 
of  the  stripper  and  ejector. 

LARGE  BLANKING  TOOLS 

Press  working  operations  are  nowadays  extended  to  include  the  manu- 
facture of  very  large  work,  sometimes  measuring  up  to  several  feet  in  length 
or  diameter.  The  illustrations  that  follow  here  are  not  by  any  means  of 
the  largest  sizes  of  blanking  dies  made  but  they  show  at  least  typical  equip- 


BLANKING  DIES 


49 


ment  for  blanking  medium  size  pieces  and  parts  that  for  the  average  shop 
would  be  considered  fairly  big  work. 

The  half-tones,  Figs.  70  and  71,  represent  blanking  tools  for  electric 
motor  disks,  the  first  illustration  showing  dies  for  circular  work  of  about 


FIG.  70.  —  Dies  for  12"  motor  blanks 


FIG.  71.  —  Tooth  for  blanking  out  an  8"  center  from  a  disk 

12  inches  diameter.     Such  tools  are  made  in  similar  form  for  plain  disks  of 
the  same  type  of  much  larger  dimensions. 

The  die  is  in  the  form  of  a  cast  iron  base  with  a  steel  cutting  ring  in- 
serted and  secured  in  the  manner  plainly  shown.  This  ring  is  about  f  inch 
thick  and  about  1J  inch  deep.  It  is  fitted  into  a  counterbored  seat  in  the 


50 


PUNCHES  AND   DIES 


interior  of  the  cast  iron  die  block  and  its  upper  face  is  beveled  at  an  acute 
angle  to  leave  a  land  at  the  top  of  J  inch  or  so  which  is  readily  ground  when 
the  die  requires  sharpening. 

The  punch  is  of  similar  construction  with  a  steel  ring  secured  to  the 
outer  end  of  a  cast  disk  acting  as  a  holder. 

INTERNAL  BLANKING  TOOLS 

In  connection  with  electrical  and  similar  work  there  are  many  parts 
that  have  to  be  manufactured  in  the  form  of  rings  with  a  large  center  cut 
out  and  the  blank  thus  removed  is  utilized  for  smaller  sizes  of  disks  and 


FIG.  72.  —  Blanking  dies  for  a  24  inch  oval 

rings.  A  typical  instance  is  shown  in  Fig.  71.  The  outer  edge  of  the  big 
blank  to  the  left  has  been  notched  previously  to  being  blanked  out  inside, 
and  the  tools  here  represented  are  for  the  latter  operation. 

For  this  second  blanking  cut,  the  disk  is  located  or  nested  on  the  die  by 
a  series  of  pins  spaced  about  its  edge  which  enter  the  notches  already  re- 
ferred to.  The  die  is  made,  up  in  the  same  manner  as  the  one  just  described 
and  its  cutting  ring  is  provided  with  the  same  beveled  face  and  narrow 
working  edge.  The  blanking  punch  is  formed,  as  in  the  case  of  the  first  one 
noted,  with  a  steel  ring  on  a  cast  center. 


BLANKING  DIES 
LARGE  OVAL  DIE 


51 


Usually  dies  of  large  diameter  blank  their  work  from  a  sheet  of  approxi- 
mate size  instead  of  from  a  long  strip.  Sometimes  the  sheet  is  trimmed 
beforehand  to  form  a  convenient  size  for  handling  in  the  press  and  to  enable 
it  to  be  located  against  stop  pins  near  the  mouth  of  the  die. 

In  the  manufacture  of  sheet  metal  ware,  such  as  aluminum  utensils, 
there  are  many  examples  of  large  press  work  seldom  seen  elsewhere.  The 


PLAN  OF  DIE 

SHOWING  SHAPE 

AND  SIZE  OF 

BLANK 


1. 

SECTION,  THROUGH  PUNCH  AN'D  DIE 

lc  FIG.  74 

Long>y'13£  Wide 

FIGS.  73-74.  —  Large  elliptical  dies 

view  in  Fig.  72,  for  instance,  represents  the  blanking  of  an  oval  in  aluminum 
which  is  later  to  be  drawn  up  into  a  shallow  pan.  This  blank  is  about  two 
feet  long.  The  tools  are  shown  in  the  press  and  their  construction  is  so 
clear  as  to  require  little  description. 

The  stops  for  loc  uing  the  aluminum  sheet  are  seen  at  the  rear  and  ends 
of  the  die,  where  they  are  so  placed  that  there  is  little  metal  left  at  the  edges 
of  the  scrap  sheet  when  the  blank  is  made. 


52 


PUNCHES  AND   DIES 


ANOTHER  ELLIPTICAL  DIE 

A  large  oval  die  shown  in  plan  and  section  in  Figs.  73  and  74  is  for  blank- 
ing black  iron  work  of  No.  28,  29,  and  30  Birmingham  gage,  or  0.012  to 
0.014  inch  thick.  The  length  of  the  piece  is  18J  inches.  The  tools  are  of 
the  pillar  type  and  the  cutting  portions  are  tool  steel  rings  fixed  to  cast  iron 
bases,  the  punch  ring  being  shrunk  into  place  and  the  die  pressed  into  its 
seat. 

The  die  is  hardened  but  the  punch  is  left  soft  so  that  when  it  becomes 
worn  it  may  be'  upset  slightly  and  resized.  This  is  a  feature  sometimes 
adopted  with  small  tools  as  well,  so  that  the  punch  size  may  be  maintained 
closely  to  the  original  size  of  the  die,  or  if  desired  upset  to  a  slightly  larger 
dimension  than  when  first  made,  in  order  to  compensate  for  slight  increase 
in  the  die  as  the  latter  becomes  enlarged  through  wear  and  because  of  the 


FIG.  75.  —  Sectional  dies  made  in  halves 

tapered  interior  which  increases  the  die  size  slightly  as  the  top  is  ground 
off  by  repeated  resharpening. 

The  die  shown,  however,  is  straight  for  a  depth  of  |  inch  and  relieved 
only  below  that  point.  So  it  retains  its  original  dimensions  until  such  time 
as  the  full  eighth  inch  has  been  ground  down. 

DETAILS  OF  PUNCH  AND  GUIDE  PINS 

The  metal  to  be  blanked  being  very  thin  for  this  size  of  work,  the  punch 
is  made  a  fairly  close  fit  to  the  die.  The  pillars  or  guide  pins  are  reversed 
from  the  usual  order,  in  that  they  are  fixed  in  the  punch  holder  and  slide 
in  the  die  base  holes.  This  arrangement  is  necessary  on  account  of  the 
large  area  of  the  press  ram  which  prevents  the  pins  from  rising  above  the 
top  of  the  die. 

It  will  be  noticed  that  the  tops  of  the  guide  bosses  on  the  die  are  practi- 


BLANKING  DIES 


53 


cally  flush  with  the  face  of  the  die.  This  insures  a  steadiness  of  action 
that  is  not  usually  obtainable  with  big  dies  of  this  kind  where  the  bosses 
referred  to  are  lower  than  the  die  face.  With  the  cutting  edge  of  the  die 
and  the  face  of  the  guides  in  the  same  plane  the  guide  pins  have  a  smooth 


Punch. 


FIG.  76.  —  Layout  of  split  die 

movement  without  liability  of  cramping  action  and  consequent  shearing 
and  injury  of  the  dies. 

In  spite  of  the  fact  that  the  punch  is  left  without  being  hardened,  its 
wear  is  negligible  for  a  long  period.  The  die  proper  although  blanking 
black  stock  with  more  or  less  scale  on  its  surface  will  run  fully  10,000  blanks 
before  it  requires  grinding. 


PUNCHES  AND   DIES 


SECTIONAL  CONSTRUCTIONS 

The  sectional  construction  for  punches  and  dies  permits  many  ad- 
vantages to  be  derived  in  connection  with  the  making  and  upkeep  of  the 
tools.  While  this  type  of  construction  is  a  great  aid  in  the  making  of  large 
dies,  it  is  also  extremely  useful  in  the  cases  of  numerous  classes  of  medium 
sized  and  fairly  small  tools,  for  it  enables  many  awkward  forms  of  dies  to 
be  made  accurately  without  serious  complications  in  respect  to  the  tool 
room  methods  of  handling,  where  with  a  solid  form  of  die  certain  portions 
of  the  work  would  be  well-nigh  impossible  of  making  up  without  a  very 
great  amount  of  tedious  labor,  much  of  it  carried  out  by  hand  processes 
entirely. 

The  sectional  die  allows  the  tool  maker  to  avoid  the  necessity  of  working 
out  various  odd  corners,  awkward  angles,  and  the  like  and  when  the  die  is 
once  completed  if  it  later  becomes  necessary  to  repair  some  portion  of  it  the 


FIG.  77.  —  Another  sectional  die 

entire  tool  is  not  affected  to  the  extent  of  requiring  replacement.  The 
problem  of  hardening  and  tempering  is  also  simplified  and  dies  of  such  size 
and  form  that  they  could  hardly  be  hardened  satisfactorily  at  all,  if  made 
in  a  single  piece,  are  under  the  sectional  construction  put  through  the  above 
processes  without  difficulty. 

A  DIE  IN  HALVES 

The  simplest  form  of  a  sectional  die,  a  split  design,  is  represented  by 
Figs.  75  and  76.  This  die  is  for  blanking  an  oval  or  ellipitical  piece  in  brass 
of  a  length  of  5|  inches  and  a  width  of  3  inches.  The  blank  is  shown  at  the 
front  of  the  die  in  the  half-tone.  The  manner  of  dividing  the  die  on  the 
center  line  is  best  brought  out  by  the  drawing,  Fig.  76. 

The  plan  view  here  shows  the  positions  of  the  die  sections .  with  each 
half  secured  by  fillister  head  screws  and  dowels.  The  two  parts  being 


BLANKING  DIES 


55 


symmetrical  about  the  center  line  it  is  possible  to  work  them  out  together 
so  far  as  the  main  machine  operations  are  concerned  and  in  case  of  distor- 
tion in  the  hardening  operation  the  individual  halve's  admit  of  convenient 
correction  by  grinding  and  lapping  and  the  abutting  joints  may  be  lapped 
down  if  necessary  to  correct  the  shorter  diameter  .or  minor  axis.  Also 
wear  may  sometimes  be  compensated  for  in  sectional  dies  by  taking  apart 
and  grinding  off  the  face  of  the  joints  and  reassembling. 

DIES  WITH  SEVERAL  SECTIONS 

The  sectional  tools  in  Fig.  77  are  for  blanking  a  piece  that  is  afterward 
formed  up  into  a  cover  for  a  machine  mechanism.  There  are  a  number  of 
sharp  corners  in  the  die  and  several  delicate,  sharply  pointed  projections. 


FIG. 


Construction  of  die  in  Fig.  77 


The  blank  is  8  inches  long  over  the  outer  corners  and  2|  inches  across  at 
the  widest  point. 

The  die  was  laid  out  in  the  sectional  form  shown  best  in  Fig.  78  where, 
as  will  be  noted,  the  different  parts  assume  a  much  simpler  outline  than 
would  at  first  appear  to  be  possible.  One  section  is  a  straight,  parallel 
piece  and  three  others  are  almost  as  simple  except  for  the  sloping  ends  and 
the  curved  points  in  which  they  terminate. 


56  PUNCHES  AND   DIES 

Here  again  several  of  the  members  may  be  laid  out  and  developed  into 
pairs.  The  machining  and  finishing  must  of  course  be  done  with  a  knowl- 
edge of  the  change  in  dimensions  likely  to  occur  when  the  parts  are  hardened 
and  corresponding  allowance  can  then  be  made  for  correction  if  necessary 
before  assembling. 

With  such  dies  it  is  customary  in  some  places  to  leave  all  members  pur- 
posely two  or  three-thousandths  long  and  wide  and  then  finish  by  grinding 
and  lapping  after  the  hardening  and  drawing  have  been  attended  to.  So, 
if  the  characteristics  of  the  particular  tool  steel  used  have  not  been  thor- 
oughly understood  or  if  the  heating  and  tempering  of  the  sections  have  not 
been  accomplished  with  a  negligible  amount  of  change  in  the  dimensions 
of  the  different  parts,  very  accurate  results  will  still  be  assured  by  the  grind- 
ing and  lapping  of  the  abutting  surfaces. 

The  foregoing  examples  of  blanking  dies  and  the  data  pertaining  to 
them  in  this  chapter  have  been  rather  closely  restricted  to  such  tools  for 
blanking  alone,  without  taking  into  consideration  the  innumerable  cases 
where  they  are  combined  or  " doubled  up"  with  other  dies  for  piercing  and 
blanking,  blanking  and  drawing,  blanking  and  forming  and  so  on.  Many 
illustrations  of  their  application  in  this  manner  will  be  presented  in  chapters 
that  follow.  Also  under  special  chapter  heads  will  be  found  a  number  of 
complete  sets  of  dies  where  the  work  starts  with  the  operation  in  the  blank- 
ing die  and  is  then  carried  successively  through  a  series  of  other  press 
tools  until  it  is  completed.  These  various  chapters  will  therefore  cover 
many  forms  and  uses  of  the  blanking  die  which  are  not  described  in  the 
present  chapter. 


CHAPTER  III 
PIERCING  TOOLS  — BLANKING   AND   PIERCING  DIES 

A  number  of  pieces  representing  certain  classes  of  press  work  as  pierced 
in  separate  dies  or  pierced  and  blanked  in  a  set  of  progressive  tools  ac- 
complishing both  operations  are  illustrated  in  Fig.  79.  Some  of  the 
examples  in  the  group  will  be  seen  to  be  duplicates  of  those  shown  in  Fig. 


FIG.  79.  —  Examples  of  blanked  and  pierced  work 

35,  but  here  they  have  been  advanced  through  another  operation,  namely 
piercing. 

PUNCH  DIES 

The  simplest  form  of  piercing  die  and  presumably  the  first  form  ever 
made  is  what  is  generally  known  as  the  " punch  die"  so  commonly  used  on 
boiler  plate  and  other  sheet  metal  up  to  very  thick  plates  preliminary  to 
riveting.  A  simple  set  of  tools  of  this  general  character  are  shown  by  Fig. 
80.  Often  the  dies  are  inserted  in  long  bed  plates  and  a  row  of  punches 
secured  in  similar  types  of  holders  are  used  for  punching  a  series  of  holes  at 
once  in  the  edge  of  a  plate. 

57 


58 


PUNCHES  AND   DIES 


Dies  of  this  kind  are  not  precision  tools  in  the  usual  sense  of  the  word, 
but  they  are  so  generally  required  in  certain  lines  of  work  that  a  few  par- 
ticulars regarding  their  construction  may  well  be  included  in  this  chapter. 

The  punch  die  proper  is  usually  a  round-bodied  tool  as  in  Fig.  81  adapted 
for  setting  in  a  circular  seat  in  its  block  and  made  with  a  beveled  top  face 


FIG.  80.  —  Simple  piercing  tools 

to  aid  in  the  piercing  out  of  the  hole  upon  the  descent  of  the  punch.  The 
punch  may  be  either  flat  ended  or  with  a  spiral  sheared  end  which  gives  a 
free  action  and  requires  less  power  for  the  performance  of  the  work.  A 
spiral  form  of  punch  is  shown  by  Fig.  82,  the  flat  end  punch  by  Fig.  83. 

The  practice  of  one 
of  our  best-known  rail- 
road shop  tool  rooms 
in  respect  to  such  dies 
should  be  of  value  here 
as  shops  of  this  kind 
make  very  wide  use  of 
punch  dies  in  their  plate 
departments.  It  is  the 
practice  in  the  shop  re- . 
ferred  to  to  make  the 
dies  with  ^V  inch  inside 
taper  or  clearance  and 
to  give  the  punch  one- 


FIG.  81 


FIG.  82 


FIG.  83 


half  that  amount  of 
taper    back    from    the 


6  =  a  + 

FIG.  84 

FIGS.  81-84.  —  Punch  dies  for  plate  work 

cutting  end,  or  ^¥  inch  as  in  the  sketch,  Fig.  84.  These  clearances  apply 
to  a  one-inch  size  of  die.  For  smaller  dies,  say  J  inch,  the  die  has  an  inside 
taper  of  ^  inch  and  the  punch  is  cleared  back  from  the  end  one-half  that 
amount.  A  proportionate  amount  of  taper  is  maintained  for  the  interme- 
diate sizes. 

The  spiral  shear  on  the  end  of  the  punch  is  given  at  A  as  f\  inch  for  1TV 


PIERCING  TOOLS  —  BLANKING  AND  PIERCING  DIES 


59 


inch  punches,  |  inch  for  1-inch  punches,  &  inch  for  f-inch  punches,  and 
below  that  the  flat  end  punch  is  used.  The  spiral  punches  are  usually 
employed  for  plate  -up  to  a  thickness  equal  to  the  diameter  of  the  punch. 
For  plates  less  than  about  |  or  \  inch  the  punches  are  left  flat. 

LIFE  OF  TOOLS 

There  is  a  considerable  amount  of  clearance  between  the  diameter  of 
punch  and  die  which  may  be  stated  to  be  as  follows:  For  sizes  up  to  \\ 
inches  allow  -fa  inch  between  punch  and  die  size.  It  is  common  practice 
to  make  the  die  A  above  and  the  punch  ^  inch  below  nominal  size  for  the 
general  run  of  work  of  this  kind.  In  ordinary  practice  the  die  will  outlast 
a  number  of  punches,  perhaps  ten  or  more.  If  starting  in  at  a  die  thickness 
of  say  \\  inch  it  will  be  ground  down  to  f  inch  before  discarding  for  the 
original  size  of  hole  and  then  it  is  ground  out  in  the  hole  for  the  next  larger 
size  of  work.  Although  such  dies  are  used  in  the  most  severe  service 
they  are  often  run  for  several  thousand  holes  before  the  tools  require 
resharpening. 

Obviously  the  holes  punched  are  allowed  a  little  more  latitude  as  to 
size  than  is  permissible  witlf  the'usual  run  of  press  work.  To  begin  with  a 
punch  for  a  |-inch  rivet  will  have  a  diameter  about  0.030  larger  than  the 
nominal  rivet  size  and  for  a  1-inch  rivet  the  punch  will  be  twice  that  amount 
larger  or  0.060  inch  over  the  nominal  diameter  of  the  rivet.  The  practice 
of  the  Pratt  &  Whitney  Company  in  this  respect  is  covered  in  the  accom- 
panying Table  No.  4  which  gives  the  size  of  punches  as  made  by  that  firm 
for  all  sizes  of  rivets  from  jf  up  to  1  inch. 

TABLE  4.  —  PUNCH  SIZES  FOR  RIVETS  FROM  ^  TO  1  INCH  DIAMETER 


Size  of  rivet. 

Size  of  punch 

Size  of  rivet 

Size  of  punch 

Inch 
A 

Inch 

0.210 

Inch 
I 

Inch 

0.690 

i 

0.280 

H 

0.740 

A 

0.340 

t 

0.800 

t 

0.410 

H 

0.860 

& 

0.470 

I 

0.940 

\ 

0.550 

if 

1.000 

& 

0.620 

i 

1.060 

A  DOUBLE  PUNCH  AND  DIE 

Another  form  of  punch  in  which  the  sheared  principle  is  applied  is 
shown  in  Fig.  85,  where  the  press  tools  are  illustrated  for  making  two  rec- 
tangular holes  in  a  steel  link  which  is  about  8  inches  long  over-all,  the 
oblong  holes  pierced  in  it  being  1.94  inch  long  by  1.365  inch  wide.  The 


60 


PUNCHES  AND  DIES 


details  of  the  tools'  are  given  in  Fig.  86  to  show  the  manner  of  inserting 
separate  dies  in  the  block  and  other  features  of  interest. 

The  stock  pierced  with  these  tools  is  half-inch  thick.     The  method  of 
providing  shear  on  the  punches  from  opposite  sides  will  be  apparent  from 


FIG.  85.  —  Double  tools  for  piercing  a  link 

the  photograph  and  drawing.     There  is  in  the  long  way  of  the  punch  an 
allowance  of  -^  inch  between  the  punch  and  die  size,  but  in  the  width 


No. 

Description 

No.  Kec. 

Material 

1 

Die  Bed 

1 

M.S. 

2 

Blanking  Die 

2 

T.S. 

3 

Blanking  Pun. 

T.S. 

4 

Punch  Holder 

M.S. 

5 

Stripper 

M.S. 

6 

Guide  Pin 

T.S. 

7 

Guide  Pin  Plate 

C.R.S. 

8 

Stop  Pin 

T.S. 

FIG.  86.  —  Details  of  link  piercing  tools 

there  is  less,  or  about  0.005  only,  for  the  fit  in  that  direction  is  more  im- 
portant owing  to  the  parts  that  enter  these  link  openings,  and  with  the 
method  of  shearing  the  punch  there  is  not  so  much  likelihood  of  the 
punches  throwing  to  one  side  sufficiently  to  shear  the  die. 


PIERCING  TOOLS  — BLANKING  AND  PIERCING  DIES 


61 


DIES  FOR  CLOSER  WORK 

Coming  now  to  the  class  of  piercing  dies  for  the  general  run  of  press- 
room work  where  sheet  metal  of  considerably  lighter  gage  is  commonly 
handled  and  where  a  close  degree  of  accuracy  is  essential,  it  may  be  pointed 
out  that  the  accuracy  of  results  is  dependent  upon  the  punch  which  is  made 
to  the  size  of  the  hole  which  is  required  to  be  pierced,  while  the  clearance 
is  allowed  in  the  die.  It  is  recommended  that  for  very  close  results  the 
punch  be  made  0.001  to  0.002  inch  larger  than  the  size  of  the  hole  required 
because  the  tendency  of  the  work  is  to  hug  the  punch  and  when  stripped 
off  to  close  up  slightly. 

The  allowances  between  punch  and  die  for  different  gages  of  stock  and 
for  various  kinds  of  metal  may  be  taken  the  same  as  the  clearances  between 
blanking  punches  and  dies  as  given  in  Table  2,  Chapter  II,  this  clearance 
depending  upon  the  thickness  of  the  stock  and  its  character  as  to  hardness, 
etc.,  and  also  upon  the  closeness  of  the  results  required.  The  table  has' 
been  computed,  as  already  explained,  to  cover  a  range  of  materials  and 
requirements  as  to  accuracy. 

TABLE  OF  PRESSURES  FOR  PIERCING 

Before  entering  into  details  of  construction  of  various  types  of  piercing 
tools  a  table  of  pressures  required  for  different  thicknesses  and  grades  of 
stock  may  be  of  interest.  Thus  Table  5  has  been  worked  out  to  cover  the 
same  gage  numbers  and  materials  as  are  included  in  Table  3  of  shearing 
pressures  in  the  chapter  on  Blanking  Dies 


FIG.  87.  —  Small  piercing  dies  FIG.  88.  —  Section  of  piercing  die 

SIMPLE  PIERCING  TOOLS  FOR  STRIP  METAL 

A  simple  form  of  open  piercing  die  is  shown  by  Fig.  87,  this  consisting 
of  a  plain  die  block,  a  round  inserted  die,  and  a  stripper  and  guide  for  the 
stock. 

The  punch  is  a  one-inch  piece  of  steel  turned  at  the  end  to  the  desired 


62 


PUNCHES  AND   DIES 


TABLE  5.  —  APPROXIMATE  PRESSURES  IN  POUNDS  FOR  PUNCHING  BRASS  AND  STEEL; 
FOR  I-INCH  DIAMETER  OF  HOLE 


Gage  U.  S.  standard  plate 

Shearing  strength  of  brass  per  sq.  in.                        =  35,000  Ibs. 
Shearing  strength  of  steel  per  sq.  in.                        =  50,000  Ibs. 
Shearing  strength  of  high  carbon  steel  per  sq.  in.  =  75,000  Ibs. 

No. 

Thickness 

Brass 

Steel 

High-carbon  steel 

28 

0.015625 

1,718    • 

2,454 

3,681 

27 

0.0171875 

1,870 

2,790 

3,928 

26 

0.01875 

2,067 

2,940 

4,395 

25 

0.021875 

2,408 

3,422 

5,168 

24 

0.025 

2,749 

3,927 

5,890 

23 

0.028125 

3,080 

4,396 

6,640 

22 

0.03125 

3,440 

4,914 

7,316 

21 

0.034875 

3,781 

5,385 

8,024 

20 

0.0375 

4,123 

5,890 

8,835 

19 

0.04375 

4,816 

6,876 

10,484 

18 

0.05 

5,498 

7,854 

11,781 

17 

0.05625 

6,190 

8,940 

13,236 

16 

0.0625 

6,872 

9,817 

14,726 

15 

0.0703125 

7,696 

10,990 

16,520 

14 

0.078125 

8,597 

12,246 

18,408 

13 

0.09375 

10,335 

14,765 

22,148 

12 

0.109375 

11,985 

17,110 

25,721 

11 

0.125 

13,744 

19,635 

29,452 

10 

0.140625 

15,505 

22,135 

33,040 

9 

0.15625 

17,150 

24,540 

36,810 

8 

0.171875 

18,912 

27,900 

39,280 

7 

0.1875 

20,672 

29,400 

43,950 

6 

0.203125 

22,321 

31,870 

47,900 

5 

0.21875 

24,080 

34,220 

51,680 

4 

0.234375 

25,729 

36,700 

55,224 

3 

0.250 

27,490 

39,270 

58,900 

2 

1 

Rule:  Multiply  thickness  of  stock  by  length  by  shearing  strength  of  material. 

diameter  for  the  hole  to  be  pierced.     The  section  through  the  dies  is  as 
indicated  in  Fig.  88. 

Piercing  dies  are  often  required  for  punching  a  number  of  holes  in  a 
piece  at  once  and  sometimes  the  holes  run  up  to  a  hundred  or  more,  as  when 
piercing  fine  openings  in  utensils  of  one  kind  or  another.  Such  tools  are 
called  perforating  dies.  Where  two  or  three  or  a  dozen  holes  or  so  are 
punched  simultaneously  the  tools  used  are  generally  known  as  gang  dies, 
particularly  when  the  holes  are  not  very  small  in  diameter.  With  fine 
punches,  however,  they  are  known  as  perforating  tools. 


PIERCING  TOOLS  — BLANKING  AND  PIERCING  DIES 


63 


Table  6  gives  dimensions  of  a  series  of  round  or  button  dies  with  3  de- 
grees clearance  inside,  and  with  20  degrees  bevel  at  the  top.  The  outside 
diameters  are  dimensioned  0.001  to  0.002  over  size  to  allow  for  pressing 
into  place  in  the  die  holder. 


TABLE  6.  —  BUTTON  DIES 


3  Included 

Angle 


D  =  diam. 

of  hole  in 

die 


0.626 

to&  0.8135 
Hto|    jl.OOl 

HtoH  k.252 

I 

ff  to  I     1.502 


A  PERFORATING  DIE 

An  illustration  of  a  perforating  die  with  several  hundred  punches  for 
piercing  the  minute  holes  in  the  bottom  of  a  thin  shell  is  given  in  Fig.  89. 
The  punches  are  all  of  small  drill  rod  inserted  in  a  holder  as  in  Fig.  90  and 


FIG.  89.  —  Perforating  dies 

fitting  closely  in  the  stripper  plate  to  give  them  a  support  at  their  cutting 
ends.  The  die  and  stripper  plate  and  holder  are  all  drilled  to  match  by 
using  -the  plate  as  a  jig.  The  construction  shows  an  open  form  of  die 
though  a  preferable  design  would  be  the  subpressed  type  which  assures 


64 


PUNCHES  AND   DIES 


alinement  of  tools  and  prevents  likelihood  of  the  small  punches  being  broken 
or  the  die  injured.  These  tools  are  shown  here,  however,  as  an  illustration 
of  a  simple  means  of  perforating  a  large  number  of  holes  at  once. 

INTERNAL  CLEARANCE  IN  PIERCING  DIES 

Piercing  and  perforating  dies  are  cleared  or  tapered  internally  on  the 
same  principle  as  blanking  dies  but  it  is  often  desirable  to  give  them  a 
greater  amount  of  clearance  than  the  J  degree  on 
a  side,  so  common  with  blanking  dies,  for  the  reason 
that  the  slugs  punched  out  of  the  stock  are  apt  to 
clog  up  in  the  dies  and  swage  together,  forming  an 
obstruction  to  satisfactory  operation  and  with  the 
smaller  sizes  of  tools  leading  often  to  broken 
punches  and  sheared  dies. 

This  difficulty  has  already  been  referred  to  in 

FIG.  90.  —  Section  through  connection  with  the  table  of  die  clearances  in  the 
preceding  chapter  and  Table  1  in  that  section  will 


perforating  dies 


therefore  be  of  value  as  showing  the  actual  clearances  in  thousandths  repre- 
sented by  various  side  angles  in  degrees.  The  table  referred  to  is  com- 
puted for  clearances  up  to  2J  degrees  on  a  side. 

The  piercing  die  is  often  reamed  out  from  the  back  with  a  standard 
taper  pin  reamer  which  gives  a  clearance  of  about  1J  degrees.  Then  there 
are  special  die  reamers  or  broaches  so  called  which  give  an  increased  taper 
equal  to  2J  to  3  degrees. 

MULTIPLE  TOOLS 

The  gang  dies  or  multiple  dies  in  Fig.  91  are  for  piercing  four  J-inch 
holes  at  once  in  J-inch  steel  pieces  which  have  been  already  formed  to 
length.  The  method  of  inserting  the  punches  will  be  of  interest.  These 
are  made  as  at  A  of  J-inch  drill  rod,  turned  down,  hardened  and  ground, 
leaving  a  head  at  the  end  which  enters  a  count erbore  in  the  block  B.  The 
block  is  of  machine  steel,  accurately  bored  for  center  distances  and  for  the 
size  of  the  punches  and  closely  fitted  in  a  seat  planed  in  the  punch  holder 
proper  C.  The  heads  of  the  four  punches  abut  against  a  hardened  and 
ground  steel  plate  D  which  is  secured  in  the  punch  holder  or  head  to 
receive  the  thrust  of  the  punches.  Three  countersunk  head  screws  hold 
the  thrust  plate  in  place  and  two  fillister  head  screws  secure  the  punch 
block  B. 

The  stripper  plate  E,  in  this  case,  serves  as  a  pressure  pad  and  is  carried 
by  four  long  fillister  head  screws.  The  pressure  behind  this  pad  when  the 
punch  is  down  is  maintained  by  a  thick  rubber  pad  at  F  which  is  used  by 
many  die  makers  in  preference  to  a  series  of  heavy  springs. 

The  die  G  is  a  tool  steel  block  bored  accurately,  and  finished  by  grinding 


PIERCING  TOOLS  — BLANKING  AND  PIERCING  DIES 


65 


after  hardening,  and  fitted  in  its  seat  in  the  die  block.     Here  it  is  secured 
by  fillister  head  screws  and  dowels. 

The  tools  are  of  the  pillar  or  subpressed  order  with  1-inch  posts  or  guide 
pins  for  preserving  alinement.  The  plan  view  of  the  die  shows  the  method 
of  forming  the  seat  for  the  four  hole  die  block  by  making  four  corner  holes 


H    Steel 


Slide  Fit 


FIG.  91.  —  Gang  piercing  die 


in  the  base  for  the  clearance  of  the  cuts  and  rounding  the  corners  of  die  G 
to  clear  accordingly. 

Table  7  covers  a  series  of  punches  for  various  sizes  of  pierced  holes.  The 
punch  bodies  at  a  point  immediately  under  the  head  are  0.001  inch  large 
for  fitting  snugly  in  the  punch  plate  as  indicated.  Such  punches  are 
readily  ground  to  size  and  fitted  to  their  places. 

BUSHED  DIES 

With  gang  dies  it  is  often  the  practice  to  make  the  piercing  dies  in  the 
form  of  bushings  which  can  be  readily  fitted  and  replaced  independently. 
This  is  of  advantage  particularly  where  there  are  quite  a  number  of  holes 
to  be  punched  and  where  the  arrangement  of  the  die  openings  is  not  along 
a  straight  line  as  they  were  in  the  last  illustration. 


66 


PUNCHES  AND   DIES 


TABLE  7.  —  PIERCING  PUNCHES 


Punch  Holder 


Diam. 

punch 

D 


In. 
<K 


I 

A 

I 

A 

I 

tt 

I 


0.251 
0.3135 
0.376 
0.4385 
0.501 
0.5635 
0.626 
HO. 6885 
0.751 


II 

If 
II 

H 
If 

if 
if 
if 
if 


In  Fig.  92  a  set  of  tools  is  shown  for  piercing  a  series  of  40  holes  in  a 
circle  of  8  in.  diameter  in  a  steel  disk  for  electrical  apparatus.  The 
pierced  disk  is  shown  at  the  right  in  the  view.  The  punches  are  inserted 
in  similar  fashion  to  those  in  Fig.  91  but  the  stripper  plate  is  backed  up  by 


FIG.  92.  —  Multiple  piercing  dies  for  disks 

a  number  of  stiff  spiral  springs  instead  of  by  a  rubber  pad.  The  die  is 
composed  of  small  bushings  hardened  and  ground  and  inserted  in  holes 
bored  in  a  circle  in  the  die  base.  These  seats  for  the  die  bushes  are  readily 
located  and  bored  by  swinging  the  work  on  the  dividing  head  of  the  milling 
machine,  and  the  punch  holder  is  similarly  treated  for  the  placing  of  the 
holes  to  receive  the  individual  punches. 

In  addition  to  the  40  holes  in  the  circle  referred  to  there  are  six  equi- 


PIERCING  TOOLS— BLANKING  AND  PIERCING  DIES 


67 


spaced  holes  punched  at  the  same  time  in  the  edge  of  the  disk.  The  posi- 
tion of  the  punches  and  die  bushings  for  this  purpose  is  seen  clearly.  Also 
the  three  stops  for  forming  a  locating  nest  for  the  round  blanks  will  be 
noticed  in  the  photograph. 

Some  interesting  problems  in  tool  work  enter  into  the  making  of  such 
dies,  locating  centers  accurately  and  boring  for  various  members.     Each 


FIG.  93.  —  Multiple  piercing  dies 

die  illustrated  in  these  chapters  might  be  made  the  basis  of  a  tool  room 
story  of  importance  if  space  were  available  for  the  purpose.  However,  the 
details  of  tool  room  operations  for  many  typical  cases  will  be  covered  in 
special  chapters  and  an  attempt  will  be  made  to  deal  sufficiently  with 
principles  and  applications  so  that  the  handling  of  general  punch  and  die 
work  will  be  made  clear  to  the  reader  not  already  versed  in  customary 
methods. 


68 


PUNCHES  AND   DIES 


ANOTHER  BUSHED  DIE 

The  tools  in  Fig.  93  illustrate  an  example  of  a  piercing  die  for  making  a 
long  row  of  holes  at  one  stroke,  this  design  also  embodying  the  principle  of 
a  bushed  die  block  which,  in  this  case,  receives  twelve  die  bushings  set 
into  the  block  as  indicated. 

The  tools  are  for  punching  /^-in.  holes  f  in.  apart.  The  dies  or 
bushings  are  f-in.  deep.  The  punches  are  f-in.  drill  rod  reduced  at  the  end 
to  the  diameter  specified.  They  are  secured  in  their  holder,  a  steel  block, 
by  set  screws.  The  stripper  has  an  angular  form,  with  the  back  rising 
against  a  set  of  rubber  plugs  or  springs  carried  as  shown  in  the  punch  holder 
proper.  A  series  of  three  short  screws  at  A,  traveling  in  vertical  slots,  limit 
the  downward  movement  of  the  stripper.  The  dotted  circles  in  the  plan 
view  of  the  punch  bring  out  the  method  of  positioning  the  rubber  sections 
to  give  ample  pressure  to  back  up  the  stripper. 

1  The  punches  in  Table  8  are  useful  where  they  are  close  to  the  edge  of 
the  punch  holder  and  therefore  reached  by  set  screws.  The  sizes  given 
range  from  J  in.  to  2  in.  and  they  are  suited  for  blanking  as  well  as  pierc- 
ing operations. 

TABLE  8.  —  PIERCING  PUNCHES  HELD  BY  SET  SCREWS 


D  = 
diam. 


Ins. 

1 
I 
i 
ft 

I 


H 
U 
H 
U 

2 


SECOND  OPERATION  PIERCING  TOOLS 

There  are  numerous  instances  where  work  previously  blanked  goes  to 
the  piercing  dies  to  have  holes  of  one  form  or  another  punched  through  in 
a  second  operation.  Several  instances  of  the  sort  have  been  included  in 
the  examples  of  work  handled  in  the  dies  illustrated  in  this  chapter,  these 
being  in  the  main  fairly  large-sized  pieces. 


PIERCING  TOOLS— BLANKING  AND  PIERCING  DIES  69 


The  round  hole  is  less 


, ;    FIG.  94.  —  Piercing  tools  for  blank  with  two  holes 

In  Fig.  94  a  pair  of  dies  are  shown  for  piercing  two  holes  in  the  ends  of 
the  rocker  shaped  lever  seen  in  the  foreground, 
than  J-in.  Diameter,  the  oblong  hole 
in  the  body  is  fV  by  j%  in.   The  piece 
is  0.140-in.  thick  and  of  steel. 

The  method  of  holding  is  to  slip 
the  work  under  the  stripper  and  hold 
it  against  the  interior  seat  or  open 
nest  by  means  of  the  handle  in  front. 
The  punches,  as  seen  in  Fig.  95,  are 
machined  upon  large  pieces  of  tool 
steel  which  form  substantial  bases  and 
these  are  secured  to  the  head  by  two 
fillister  screws  and  two  dowels  each. 
The  larger  punch  circle  is  cut  out  at 
the  back  to  admit  the  edge  of  the 
other  flange  to  allow  the  right  center 
distance  to  be  secured.  The  form  of 
the  punches  is  very  rigid  and  there  is 
little  probability  of  their  springing. 
This  design  of  punch  with  solid  back, 
which  is  turned  down  to  give  the 
punch  size,  is  a  commendable  one,  for 


FIG.  95.  —  Double  piercing  punches 


it  provides  a  rigid  seat  and  a  punch  that  cannot  spring  as  would  be  the  case 
were  it  straight  all  the  way  back  and  inserted  simply  in  the  holder  forming 
the  head  of  the  subpressed  dies. 


70 


PUNCHES  AND   DIES 


The  dies  are  round  and  of  the  proper  size  inserted  in  the  base  block. 
The  stripper  plate  is  countersunk  around  the  holes  to  allow  the  short  stiff 
punches  to  enter  and  clear  at  the  point  of  enlargement. 

BLANKING  AND  PIERCING  DIES 

After  all,  the  most  commonly  found  cases  of  piercing  operations  are 
where  they  are  in  conjunction  with  blanking,  the  required  holes  being  first 
pierced  in  the  strip  of  stock  and  the  next  stroke  of  the  Dress  causing  the 


FIG.  96.  —  Progressive  piercing  and  blanking  dies  for  a  special  washer 


< <*«&  B  -  2nd  Stage  A  -  1st  Stage  < «^£ 

Blanking  Piercing 

FIG.  97.  —  Successive  steps  in  making  the  washer 

piece  to  be  blanked  out.  A  simple  but  good  illustration  of  the  principle 
is  presented  in  Fig.  96  which  shows  a  round  washer  with  four  small  holes 
pierced  at  quarters  around  the  circle. 

The  piercing  tools  are  located  at  the  right  hand  or  the  end  where  the 
stock  enters.  The  center  hole  is  here  punched  out  and  the  four  smaller 
holes  pierced  as  at  A,  Fig.  97.  The  next  advance  of  the  stock  allows  the 
strip  of  metal  to  be  located  correctly  by  the  pilot  on  the  end  of  the  blanking 


PIERCING  TOOLS— BLANKING  AND  PIERCING  DIES 


71 


punch  so  that  as  that  punch  passes  through  the  stock  the  washer  is  blanked 
out  concentrically  as  at  B,  Fig.  97. 

A  substantial  type  of  punch  for  either  piercing  or  blanking  and  one  that 

TABLE  9.  —  PUNCHES  HELD  BY  SCREW  TAPPED  IN  FROM  THE  TOP 


_L 


D  = 

diam.  of 
punch 


1 

H 
it 
1* 

U 

2 


is  secured  in  practically  the  same  manner  as  the  two  larger  ones  in  Fig.  96 
is  covered  in  various  sizes  by  Table  9.  This  construction  provides  for  the 
securing  of  the  punch  in  its  holder  by  means  of  a  fillister  head  screw  tapped 
in  from  the  top  as  indicated.  This  method  is  the  one  used  with  many  such 
punches  as  are  illustrated  in  Fig.  96. 

TABLE  10.  —  PILOTS  FOR  PROGRESSIVE  BLANKING  PUNCHES 


Ins. 


\ 


tt 


•h 

Flat 
end 
Flat 
end 
Flat 
end 
Flat 
end 
Flat 
end 


1A 
1A 
1A 
1A 
1A 
1A 
1A 

1A 
1A 
1A 
1A 
1A 


72 


PUNCHES  AND   DIES 


PILOTS 

The  pilot  is  inserted  in  the  blanking  punch  and  is  made  to  a  long  radius, 
equal  at  least  to  the  diameter  of  the  pilot  body.  This  question  of  pilots  is 
of  interest  as  they  are  so  extensively  used  in  connection  with  progressive 
dies.  Table  10  herewith  is  laid  out  to  cover  pilot  dimensions  for  the  type 
of  punch  which  is  held  by  a  fillister  head  screw  tapped  in  from  the  top  of 
the  punch  holder.  The  same  dimensions  apply  also  to  pilots  for  the  other 

TABLE  11.  —  PROGRESSIVE  BLANKING  PUNCHES  WITH  PILOTS 
For  Pilot  Dimensions  Refer  to  Table  10 

Make  L  for  All  Punches  Equal  to  Pilot  Shank  +  |  In.     (See  Table  10  for  Pilots) 


Rivet  Over 


D  =  diam. 

* 

#2 

^3 

4 

B 

* 

Ins. 
1 

Iff 

1ft 

TS 

Iff 

1A 

1A 

Iff 

ITS 

-rz 
1 

Iff 

ITS 

JL. 

Iff 

i 

f 

Iff 

Mi 

iff 

ITS 

ift 

! 

* 

TS 

1 



1ft 

1ft 

i 
* 

T6 

1 

H 

l" 

ITS 

f 

TS 

1 

li 

l-3- 

H 

ft 

1ft 

l-3- 

1A 

H 

If 
If 

1ft 

1ft 

1ft 

A 
ft 

1ft 
if 

2 

l-3- 

1A 

If 

ft 

ift 

1A 

If 

ITS 

24 

1_3_ 

11 

ft 

Ifs 

21 

J  » 

If 

ITS 

2f 

1A 

2 

ft 

2TS 

PIERCING  TOOLS— BLANKING  AND  PIERCING  DIES 


73 


classes  of  punches  whose  proportions  are  given  in  Tables  7, 8,  and  11,  and  in 
all  cases  the  pilots  should  be  ground  or  otherwise  finished  on  the  stem  or 
shank  to  a  press  fit  in  the  ends  of 
the  blanking  punches. 

Ordinarily  the  pilots  can  be 
made  of  drill  rod.  In  the  smaller 
sizes,  as  indicated  in  the  tables,  the 
point  of  the  pilot  is  rounded  to  a 
definite  radius  given  in  Column  D, 
Table  10.  For  larger  sizes  of  pilots 
the  bottom  end  is  flat,  reducing  the 
length  accordingly,  and  the  corners 
are  rounded  to  a  radius  of  ft  in. 
These  proportions  are  varied  where 
necessary  but  for  a  wide  range  of 
work  they  have  proved  satisfactory. 


Die  Holder 


PROGRESSIVE  DIE  SECTION 

The  sectional  view,  Fig.  98,  rep- 
resents one  standard  form  of  con- 
struction for  progressive  dies  with    FlG-  98.  —  Construction  for  progressive  dies- 
the  tools  shown  on  the  vertical  center  line  of  the  blanking  punch.     The  die 


Guide  Pins 


FIG.  99.  — Progressive  tools  for  piercing  and  blanking  a  rectangular  part 

is  here  seen  secured  in  its  holder  or  base  by  fillister  head  screws  and  dowels 
which  are  independent  of  those  used  for  attaching  the  stripper  to  the  die. 


74 


PUNCHES  AND   DIES 


The  screws  for  the  latter  purpose  are  short  countersunk  head  screws  which 
may  be  removed  to  permit  the  stripper  to  be  taken  off  and  the  die  to  be 
examined  or  ground  without  disturbing  it  in  its  holder. 


Dowels 


Blanking 
Die 


Spring 


FIG.  100.  —  Details  of  tools  in  Fig.  99 


This  is  an  advantage  over  the  alternative  construction  commonly  used, 
where  one  set  of  screws  and  dowels  are  employed  for  both  stripper  and  die. 

ANOTHER  EXAMPLE 

The  piercing  and  blanking  tools  in  Figs.  99  and  100  punch  two  small 
rectangular  holes  in  the  german  silver  stock  and  blank  out  the  piece  to  the 
dimensions  given  in  the  latter  drawing.  These  engravings  show  clearly 


PIERCING  TOOLS— 'BLANKING  AND  PIERCING  DIES 


75 


the  method  of  making  the  main  punch  from  a  solid  block  and  inserting  in  its 
body  the  two  piercing  punches,  which  are  formed  with  round  bodies  for 
that  purpose. 

The  punch  rests  squarely  upon  its  base  which  has  ample  area  to  give  it 
security  and  one  fillister  head  screw  and  two  dowels  fasten  it  in  place.  The 
blanking  portion  of  the  punch  is  machined  up  mainly  by  milling  and  the 
large  fillets  in  all  corners  give  a  rigidity  that  is  most  desirable  in  tools  of 
this  character.  The  two  holes  for  the  piercing  punches  are  located  ac- 
curately and  bored  through  for  the  enlarged  shanks  and  the  piercing  por- 
tions are  left  purposely  short  to  provide  further  stiffness. 

The  piercing  dies  are  of  the  button  type  inserted  in  seats  in  the  main 
die  in  which  they  are  pressed  snugly.  A  stop  of  the  trigger  type  is  carried 


FIG.  101.  —  Progressive  dies  for  an  interrupted  gear  wheel 

in  the  stripper  as  represented,  and  a  finger,  spring-actuated  and  adapted 
to  press  inward  and  hold  the  stock  against  the  guide,  is  included  at  the  side 
of  the  stop  as  seen  in  the  sketch. 

It  will  be  noticed  that  the  piercing  punches  are  shorter  than  the  blank- 
ing punch  by  a  sufficient  amount  to  allow  the  latter  punch  to  strike  through 
the  stock  before  the  piercing  punches  enter  the  work.  This  permits  the 
blanking  punch  to  locate  the  work  properly  by  means  of  its  pilots  and  also 
prevents  any  undue  stress  being  imparted  to  the  piercing  punches  by  the 
action  of  the  larger  blanking  punch  upon  striking  the  stock. 


76 


PUNCHES  AND   DIES 


36  Teeth  to  Circle    60  Included. 
29  Teeth  on  Disc. 


TOOLS  FOR  A  TOOTHED  PIECE 

A  set  of  tools  which  combine  in  a  different  manner  certain  of  the  features 
of  some  of  the  dies  already  described  are  illustrated  by  Fig.  101.  These 
produce  the  piece,  Fig.  102,  from  TV-in.  steel  stock. 

The  large  piercing  punch  for  the  center  of  the  gear  disk  is  made  with  an 
enlarged  base,  as  in  previously  shown  constructions,  and  the  four  small 
piercing  punches  are  inserted  therein,  the  group  of  five  punches  then  being 

secured  by  two  screws  and  two  dowels 
as  plainly  seen.  The  blanking  punch 
is  turned  with  a  locating  hub  and 
secured  by  screw  and  dowels  from  the 
top  of  the  punch  holder.  The  punch 
teeth  are  milled  by  special  cutters  and 
similar  cutters  are  used  for  making 
broaches  for  working  out  the  teeth  in 
the  die  which  is  finished  out  in  the  teeth 
by  machine  filing,  broaching,  hand 
filing,  and  lapping. 

With  the  teeth  worked  out  some- 
where near  to  size,  the  broach  is  forced 
in  g^  in.  or  so,  under  a  hand  press,  then 
hand  filing  is  resorted  to  to  remove 
the  stock  to  the  outline  set  in  by  the 
broach,  after  which  the  broach  is  again 
applied  and  forced  down  a  little  further,  the  process  being  repeated  and 
filing  being  done  to  the  point  broached  until  the  broach  has  been  passed 
down  through  the  die.  , 

The  details  of  operations  on  dies  of  this  class  with  accurate  tooth  forms 
to  produce,  will  be  taken  up  at  length  in  another  section  of  this  book.  The 
dies  just  referred  to  are  shown  at  this  point  to  illustrate  an  interesting  form 
of  progressive  tool  that  is  put  together  in  substantial  fashion. 

A  SHEARED  DIE 

The  die  in  Fig.  103  is  for  producing  a  flat  blank  from  rather  heavy  stock, 
and  to  ease  the  action  on  the  tools  and  work  and  produce  a  smoother,  better 
job,  the  shearing  principle  has  been  adopted  for  the  die  face.  The  pro- 
gressive feature  for  the  piercing  and  blanking  in  sequence  is  apparent  and 
the  arrangement  of  piercing  punch  and  the  pilot  in  the  blanking  punch  is 
likewise  clear.  The  blanking  punch  is  made  with  a  wide  base  to  seat  in 
the  crosswise  channel  in  the  holder  and  the  screws  are  run  in  from  the  rear. 

The  shear  on  the  die  face  is  in  the  form  of  two  concave  surfaces  covering 
about  two-thirds  the  length  of  the  die.  The  stripper  has  been  removed  in 


U/M  Ream 


Teeth 


f  No.  52  Holes  C.'sk 

/64  Diam. 
Flat  Top  &  Bottom 

Drum  Reverse  Lock  Disc. 
Vi6"x  l%"H.Hard  Stock. 
FIG.  102.  —  Detail  of  gear  wheel 


PIERCING  TOOLS— BLANKING  AND  PIERCING  DIES  77 


I 


c? 


L^^% 

K  x.* 


FIG.  103,  —  Progressive  tools  with  sheared  die  face 


i1. 


FIG.  104.  —  Piercing  and  blanking  tools  for  a  typewriter  part 


78 


PUNCHES  AND  DIES 


the  view  to  permit  the  die  to  be  shown  more  clearly.  The  concave  shear 
is  of  course  readily  ground  and  the  die  is  therefore  easily  kept  in  good  con- 
dition for  operation. 

PIERCING  A  SLOT 

Piercing  dies  are  often  required  for  forming  irregular  openings,  long 
slots,  and  the  like  as  well  as  for  making  round  and  square  holes  in  the  work. 
An  example  of  a  particularly  neat  set  of  tools  of  this  character  is  represented 
by  the  piercing  and  blanking  progressive  die  in  Fig.  104.  The  piece 

blanked  and  pierced  is  shown  by 
the  detail,  Fig.  105.  This  is  a 
sheet  steel  typewriter  part  &-in. 
thick  and  is  later  bent  in  forming 
dies  to  finished  shape.  Only  the 
blanking  and  piercing  tools  will  be 
shown  at  this  point  however. 

The  well-proportioned  punch 
and  die  parts  are  all  shown  in  the 
assembly  drawing,  Fig.  104.  The 
interesting  feature  of  the  tools  in 
the  present  connection  is  the  pro- 
vision for  piercing  the  opening  at 
A,  Fig.  105,  with  the  punch  A' 
and  die  A2,  Fig.  104,  so  that  when 
the  work  advances  to  the  blanking 
position,  the  cutting  out  of  the 
blank  is  accomplished  in  die  open- 
ing B,  by  the  punch  which  shears 
across  the  lower  end  of  the  slot  A,  Fig.  105,  and  thus  leaves  that  slot  open 
at  the  end  as  required.  This  is  a  method  frequently  resorted  to  where  one 
or  more  narrow  slots  are  required  with  one  end  open  as  in  the  form  of, 
say,  a  toothed  comb;  the  oblong  openings  or  slots  can  be  pierced  as  com- 
pletely enclosed  holes  and  at  the  next  stage  or  blanking  process,  the  ends 
are  opened  by  the  blanking  out  of  the  piece. 

There  are  also  in  the  blank  shown  two  small  round  holes  that  are  pierced 
by  the  two  inserted  punches,  0.096  in.  in  diameter.  The  pilot  for  locating 
the  work  for  the  blanking  is  a  rectangular  piece  shown  at  C  which  is  fas- 
tened by  a  screw  and  two  small  dowels  to  the  face  of  the  blanking  punch  D. 
The  blanking  punch  is  made  in  one  piece  of  tool  steel  as  indicated.  The 
tool  steel  piercing  punch  A'  for  the  slot  is  inserted  in  a  separate  steel  plate 
E  which  is  also  bored  to  receive  one  of  the  small  round  punches  F.  The 
other  small  round  punch  G  is  inserted  in  a  hole  bored  in  the  body  of  the 
blanking  punch  D.  Each  of  the  two  punch  bodies  D  and  E  is  secured  by 


FIG.  105.  —  Detail  of  blank  produced  in  the 
tools  in  Fig.  104 


PIERCING  TOOLS— BLANKING  AND  PIERCING  DIES 


79 


two  fillister  head  screws  and  two  dowels  fitted  in  from  the  top  of  the  punch 
holder.  Both  punches  fit  snugly  in  the  seat  planed  out  3  in.  wide  by 
f-in.  deep  in  the  face  of  the  punch  holder.  With  the  divided  construction 
shown  it  is  possible  if  required  to  grind  and  lap  the  joining  edges  of  the 
punch  bodies  to  bring  the  spacing  between  centers  to  closest  degree  of 
accuracy. 

It  will  be  apparent  from  the  plan  view  of  the  die  that  the  position  of  the 
work  as  pierced  and  blanked  is  such  as  to  take  a  minimum  of  stock,  the 
angle  to  which  the  piece  is  set  allowing  the  hooked  projection  to  be  blanked 
from  the  tongue  left  by  the  preceding  blank. 


Blonking  Die  and  Punch  for  Countersunk  Washers 

FIG.  107  FIG.  108 

FIGS.  106-109.  —  Blanking  die  and  punch  for  countersunk  washers 

A  THREE-STAGE  SET  OF  DIES 

Piercing  operations  in  progressive  dies  are  oftentimes  combined  with 
other  work  than  merely  blanking,  three  or  four  distinct  sets  of  tools  being 
then  carried  in  the  one  pair  of  holders  so  that  the  job  advances  from  one 
die  to  the  next  until  completed,  just  as  with  the  piercing  and  blanking  tools 
already  illustrated. 

An  illustration  of  a  piece  of  work  requiring  piercing,  forming,  and 
blanking  as  produced  in  a  progressive  die  is  shown  by  Fig.  106.  This  is  a 
counter-sunk  washer  made  from  f-in.  rolled  stock. 

The  dies  are  seen  in  Fig.  107,  and  the  trigger  gage  or  stop  for  automati- 
cally locating  the  stock  is  shown  by  the  detail  in  Fig.  108.  The  counter- 
sinking to  60  degrees  was  originally  performed  in  the  drill  press  but  this 
was  found  a  comparatively  slow  process  and  so  the  press  tools  were 
designed  as  shown  to  take  care  of  the  counter-sinking  also,  this  present 


80 


PUNCHES  AND  DIES 


arrangement  producing  3500  large  counter-sunk  washers  and  7000  J-in. 
plain  washers  per  hour.  The  latter  are  blanked  out  from  the  space  left 
between  the  large  washer  blanks,  as  indicated  in  Fig.  109  which  shows  the 
scrap  and  gives  an  idea  of  the  small  amount  of  steel  wasted  in  the  work. 

The  large  washer  shown  pierced  and  drawn  down  at  A,  Fig.  106,  has 
been  passed  through  the  first  operation  in  the  die  N  and  punch  L,  Fig.  107. 


(O) 


(m 


FIG.  110.  —  Multiple  piercing  tools  for  a  sheared  plate 

The  surplus  stock  is  here  drawn  to  the  bottom  by  the  punch  L  which,  con- 
tinuing downward,  pierces  a  |-in.  hole  through  the  stock.  Upon  the  up- 
stroke of  the  punch  the  strip  of  steel  is  advanced  to  allow  the  blanking 
punch  H  to  remove  the  J-in.  washer.  At  the  same  time  the  first  opera- 
tion is  repeated. 

As  the  stock  again  advances  it  comes  to  the  punch  G  and  die  P.  The 
dished  stock  shown  at  A,  Fig.  106,  is  now  flattened,  forming  the  desired 
counter-sink,  and  at  the  same  time  it  is  embossed  by  the  punch  G  and  the 


PIERCING  TOOLS  — BLANKING  AND  PIERCING  DIES 


81 


die  P.  As  the  stock  is  advanced  for  the  third  operation  the  counter-sunk 
washer  is-  blanked  out  by  the  die  S  and  the  punch  F  which  is  provided  with 
a  pilot  Q,  inserted  in  the  manner  shown. 

The  punch  holder  B  is  made  of  cast  steel  and  the  die  plate  C  of  cast 
iron.     They  are  properly  alined  by  the  guide  pins  D  and  the  bushings  E 


FIG.  111.  —  The  plate  as  pierced  with  the  tools  in  Fig.  110 


FIG.  112.  —  A  sectional  die  for  piercing  a  series  of  slots 

which  are  pressed  into  position  and  lapped  to  fit  the  guide  pins.  Under 
operating  conditions  the  guide  pins  are  well  lubricated.  The  punches 
Fj  G,  H>  R,  and  J  are  held  in  position  by  taper  pins.  The  dies  are  pressed 
into  position  in  their  seats  in  the  die  plate  C. 

The  stripper  Z  is  held  in  place  by  cap  screws  K.    The   perforating 
punch  L  is  secured  by  the  headless  screw  M.    The  die  N  is  adjustable 


82 


PUNCHES  AND   DIES 


vertically  in  its  seat  by  means  of  the  threaded  sleeve  T.     Small  pinholes 

in  the  Bottom  and  a  pin  spanner  are  provided  for  purposes  of  adjustment. 

Referring  again  to  the  trigger  stop  or  gage,  Fig.  108,  this  works  auto- 


. 

9 

8 

7 

6 

5 

4 

3 

2 

1 

!' 

f 

0 

0 

0 

0 

0 

0 

0 

0 

J 

1 

1 

1 

1 

1 

1 

1 

1 

1 

2 

2 

2 

2 

2 

2 

2 

2 

2 

4 

3 

8 

3 

3 

3 

3 

3 

3 

3 

M 

5 

5 

5 

5 

5 

5 

5 

5 

5 

6 

6 

0 

G 

6 

6 

G 

6 

0 

8 

8 

8 

8 

3 

8 

8 

8 

8 

n 

9 

9 

9 

9 

9 

9 

9 

9 

-T  

I 

<- 

->- 

_j 

J5( 

" 

->- 

V 

-&-0. 

52     'y      " 

^                                                                                                                         n  r\c\r\ 

„ 

'1 

FIG.  113.  —  The  work  with  slots  pierced 


FIG.  114.  —  Sectional  slot  die  details 

matically  under  operating  conditions  by  the  proper  adjustment  of  the  set 
screw  and  lock  nut  R  which  is  here  seen  in  the  side  elevation  of  the  auto- 
matic spacing  gage.  As  the  punch  descends,  the  screw  strikes  at  X  and 
causes  the  inner  end  of  the  gage  A  to  be  raised  out  of  the  hole  B,  Fig.  109, 
in  the  edge  of  the  stock. 


PIERCING  TOOLS  — BLANKING  AND  PIERCING  DIES 


83 


PLAN  OF  DIE 

FIG.  115 
FIG.  115-116.  —  Plan  of  slot  piercing  punch  and  die 


84  PUNCHES  AND  DIES 

DIES  WITH  SPRING  PLATE  OK  STRIPPER  FOR  THE  PUNCHES 

The  tools  in  Fig.  110  for  piercing  the  six  holes  in  the  plate,  Fig.  Ill, 
resemble  somewhat  in  appearance  a  compound  die  in  that  they  carry  a 
spring  actuated  pressure  pad  and  stripper  for  the  punches.  The  latter  are 
i-in.  diameter  and  the  plate  operated  upon  is  a  steel]  member  ^-in.  thick 
for  a  coin  register.  The  dies  are  for  piercing  only  as  the  piece  is  blanked 
in  a  previous  operation. 

The  six  dies  are  inserted  in  the  steel  plate  as  indicated  and  the  die 
holder  fastened  by  screws  and  dowels  to  the  base  plate.  The  punches  are 


FIG.  117.  —  Longitudinal  section  through  punch  and  die 


made  with  f-in.  bodies  and  with  enlarged  head  so  that  they  are  seated  in 
the  steel  punch  plate  which  is  itself  attached  to  the  main  head  by  fillister 
head  screws  and  dowel  pins.  There  are  six  heavy  springs  for  controlling 
the  stripper  plate. 

The  locating  stops  for  the  work  are  a  series  of  fVm-  pins  inserted  in 
the  die  as  shown. 

This  type  of  die  is  used  extensively  for  various  classes  of  work  where 
holes  are  required  to  be  pierced  in  parts  already  blanked.  The  general 
arrangement  of  the  punches  and  stripper  are  quite  similar  to  that  found  in 
the  construction  of  the  smaller  set  of  tools  in  Figs.  89  and  90  for  perforating 


PIERCING  TOOLS— BLANKING  AND  PIERCING    DIES 


85 


the  bottom  of  the  article  there  shown.  The  dies  in  Fig.  110,  however,  are 
of  the  pillar  type  which  insures  alinement  of  the  tools  at  all  times.  The 
arrangement  of  the  springs  for  the  stripper  is  along  the  lines  followed  very 
often  with  compound  dies  where  work  is  blanked  and  pierced  at  a  single 
stroke  in  distinction  from  the  follow  dies  shown  in  this  chapter  where  the 
piercing  is  done  first  and  the  stock  then  advanced  to  a  second  position  for 
the  blanking  out  of  the  piece. 

Details  of  construction  of  compound  dies  are  taken  up  in  the  chapter 
which  follows.     There  are  a  few  more  types  of  piercing  dies  to  be  shown 


9-T.S.  Punches 


ii  1 1 1  iTm  1 1 1  i 


FIG.  118.  —  Cross  section  through  punch  and  die 

in  the  present  chapter  and  one  of  these]which  embodies  some  very  interest^ 
ing  features  is  represented  by  Fig.  112. 

A  SECTIONAL  SLOT-PIERCING  DIE 

The  press  tools  in  this  view  accomplish  the  piercing  of  the  series  of  nine 
slots  in  the  steel  cover  plate  shown  in  the  background  of  the  photograph. 
The  piece  is  afterward  formed  up  for  a  dial  cover  for  a  calculating  machine. 
It  is  cut  out  first  to  a  blank  7.920  by  5.485  in.  as  in  Fig.  113  and  is  then 
stamped  in  dies  which  mark  the  numerals  seen  between  the  slots  and  at 
their  ends.  The  slots  are  then  formed  with  the  piercing  dies,  Fig.  112, 


86 


PUNCHES  AND   DIES 


which  operation  naturally  follows  the  stamping  in  of  the  characters  in  the 
face  of  the  blank  in  order  to  avoid  the  distortion  that  would  be  caused  by 
the  stamping  of  the  numbers  if  done  after  the  slots  were  made< 

The  slots  are  practically  ^Vin.  wide  and  the  width  occupied  by  one 
slot  and  the  adjoining  stamped  section  is  0.356  in.  The  punch  and  die 
are  shown  with  stripper  removed  in  the  view  in  Fig.  114  and  a  plan  view  of 
the  inserted  sections  for  both  members  is  given  in  Figs.  115  and  116.  The 
view,  Fig.  114,  shows  the  stop  gage  and  guide  for  the  blank  at  rear  and  side. 
The  drawings,  Figs.  117  and  118,  show  respectively  longitudinal  and  cross 
sections  and  a  detail  of  one  of  the  punch  and  die  sections  is  reproduced  in 
Fig.  119.  The  different  drawings  referred  to  give  a  clear  idea  of  all  con- 
struction features. 


/^Clearance  DIE  SECTION 


FIG.  119.  —  Detail  of  punch  and  die  parts 

THE  DIE  PARTS 

From  Figs.  115,  117,  and  118  it  will  be  seen  that  the  tool  steel  die  sec- 
tions are  let  into  a  steel  plate  or  holder  which,  in  turn,  is  secured  in  a  seat 
in  the  base  casting  by  means  of  fillister  head  screws.  Here  the  die  sections 
or  blades  A  are  fitted  snugly  together  and  clamped  at  the  ends  by  the  steel 
strips  shown  at  B.  The  die  sections  are  made  with  their  ends  of  the  right 
width  to  give  the  exact  spacing  required  between  slots  and  the  narrow 
central  portions  are  finished  precisely  central  with  the  widened  ends. 
They  are  finished  J  degree  taper  on  the  sides  to  give  the  clearance  desired 
between  them,  or  the  same  as  if  they  were  all  worked  out  from  a  solid  piece 
of  tool  steel. 

The  sections  were  milled  out  from  stock  of  suitable  width,  a  few  thou- 
sandths being  left  for  grinding  and  lapping  to  exact  dimensions,  then  they 


PIERCING  TOOLS— BLANKING  AND  PIERCING  DIES  87 

were  hardened  and  drawn,  and  then  placed  on  the  magnetic  chuck  for  sur- 
face grinding.  This  was  followed  by  lapping  dead'  to  size. 

It  may  appear  that  the  sections  could  have  been  made  simpler  for 
facilitating  the  finishing  processes  but  there  are  certain  decided  advantages 
with  the  form  shown  where  the  long  body  is  central  with  the  wide  ends. 
For  instance,  the  simplest  method  to  occur  to  one  might  be  the  construction 
at  X,  Fig.  120,  where  the  die  blades  a  are  straight  from  end  to  end  and  are 
spaced  by  blocks  6  equal  to  the  width  of  slot  required  in  the  work.  This 
arrangement,  however,  multiplies  the  number  of  parts,  and  increases  cor- 
respondingly the  number  of  surfaces  to  be  finished  accurately;  moreover, 
once  completed,  there  is  some  question  if  there  might  not  be  a  tendency 
for  the  long  blades  to  spring  away  slightly  from  the  bearing  joint  between 
the  spacing  sections,  thus  giving  a  less  rigid  construction  than  the  one 
actually  employed. 

Another  possible  design  is  represented  at  Y,  Fig.  121.  Here  the  recess 
for  the  die  opening  is  all  at  one  side  of  the  section,  the  ends  being  of  the 


b. 

1 

\N 

j 

K 

fy 

v^l 

„  w 

X 
FIG.  120 

i 

Y. 
FIG.  121 

1 

FIGS.  120-121.  —  Other  possible  forms  of  die  sections 

same  width  as  when  the  symmetrical  form  of  Fig.  115  is  used.  While  there 
is  some  advantage  here  in  doing  all  the  cutting  in  of  the  metal  from  one 
side  with  a  plain  flat  surface  opposite,  there  is  still  a  difficulty  in  con- 
nection with  the  hardening  that  is  likely  to  offset  this  in  a  measure.  As 
with  any  member  that  is  offset,  eccentric  or  so  shaped  that  the  cross- 
sectional  area  is  unevenly  distributed  in  relation  to  the  axis  of  the  piece  as 
a  whole,  there  is  likely  to  be  distortion  when  the  work  is  hardened  and  this 
necessitates  provision  for  the  removing  of  more  material  by  grinding  after 
the  work  has  been  through  the  fire.  Experience  on  other  work  with  the 
two  forms  of  die  sections  at  X  and  Y  led  the  designers  of  the  sectional  die 
described  to  use  the  form  of  inserted  member  illustrated  in  Fig.  115. 

THE  PUNCHES 

The  form  of  the  punch  sections  is  shown  by  the  drawings  to  be  sym- 
metrical also,  the  blades  being  placed  centrally  with  their  backs  and  per- 
mitting of  ready  machining  and  of  accurate  finishing  by  grinding  and 
lapping. 

These  punch  sections  are  secured  as  at  C,  Figs.  115  and  118,  in  a  steel 


88 


PUNCHES  AND   DIES 


holder  or  plate  which  is  machined  out  to  let  the  sections  enter  as  a  snug  fit 
when  finished  to  correct  length  and  thickness.  The  punch  sections  are 
also  secured  by  small  fillister  head  screws  and  dowels  as  represented  in  the 
plan  view. 

The  flat  steel  holder* or  punch  plate  is  J-in.  thick  through  the  bottom 
and  is  itself  fastened  to  and  located  on  the  cast  head  by  screws  and  dowel 
pins.  The  two  members,  base  and  head,  of  this  set  of  tools  are  alined  and 
kept  in  condition  by  the  large  guide  posts  or  pillars  at  the  back. 

The  punches,  it  will  be  noticed,  are  adapted  for  a  shearing  cut  on  the 
metal,  by  having  three  concave  portions  along  their  cutting  edges  which  are 


FIG.  122 
FIGS.  122-123.  —  Side  piercing  tools 

ground  in  with  the  circumference  of  the  wheel  so  that  they  are  kept  sharp- 
ened as  readily  as  if  they  were  of  the  conventional  flat  form.  This  method 
of  shearing  allows  the  work  to  be  slotted  with  the  narrow  closely  spaced 
punches  without  danger  of  " dragging"  the  metal  and  producing  rough 
irregular  edges  along  the  slots. 

SIDE  PIERCING  TOOLS 

There  are  instances  where  work,  cylindrical  or  other,  requires  piercing 
from  the  side  and  the  punches  in  such  cases  are  operated  radially  or  toward 
the  .center  of  the  piece  by  tapered  or  bevel-faced  plungers  carried  by  the 
upper  member  of  the  die  set  and  acting  against  pressure  springs  which 


PIERCING  TOOLS— BLANKING  AND  PIERCING  DIES  89 

return  the  punch  slide  to  normal  position  upon  the  up-stroke  of  the  press. 
A  typical  case  is  illustrated  by  Fig.  122. 

In  some  cases  a  large  number  of  holes  are  pierced  simultaneously 
through  the  work  by  the  necessary  number  of  punches  all  carried  by 
sliding  members  operated  in  similar  fashion  to  the  ones  described.  And 
these  side  piercing  punches  may  be  designed  to  be  operated  either  toward 
the  center  by  some  form  of  closing-in  device,  or  on  the  other  hand  expanded 
and  forced  outwardly  by  a  tapered  plunger  or  its  equivalent  at  the  center. 
The  direction  of  the  working  stroke  of  the  punch  depends  upon  the  size 
and  character  of  the  piece  to  be  pierced. 

Referring  now  to  Fig.  122,  this  shows  a  set  of  piercing  tools  for  punch- 
ing two  holes  in  opposite  sides  of  the  square  tube  .seen  at  the  right  in  the 
drawing,  Fig.  123.  The  tube  is  of  steel,  rf-m-  square  inside  and  the 
method  of  supporting  in  the  dies  is  to  slip  the  piece  of  work  over  the  mem- 
ber A  which  may  be  called  a  horn  die  in  this  instance,  as  it  projects  in  the 
form  of  a  bar  from  the  shank  which  is  fitted  in  the  wall  at  the  back  of  the 
die  base.  The  support  A  is  finished  out  through  the  sides  to  form  the  die 
openings  and  a  slot  is  cut  in  the  bottom  at  B  to  allow  the  slugs  to  drop 
through.  The  shape  of  the  die  is  seen  at  C  where  the  hole  is  shown  y'V-in. 
wide  by  -ft-in.  long  with  the  front  end  formed  to  a  half  circle. 

/ 

THE  PUNCHES  AND  HOLDERS 

The  two  side-piercing  punches  are  set  into  holders  as  at  D,  the  blocks  E 
being  adapted  to  travel  longitudinally  to  force  the  punches  through  the 
work  when  the  plungers  F  descend  with  the  down  stroke  of  the  press  slide. 
These  plungers  are  secured  in  a  regular  punch  holder  or  head  and  are  of 
tool  steel,  hardened.  They  are  machined  to  an  angle  of  30  degrees  for  a 
portion  of  their  length  and  a  corresponding  slope  is  formed  upon  the  rear 
ends  of  the  punch  slides  E,  E.  The  plungers  F  are  cylindrical  except  for 
the  sloping  portion  referred  to,  and  they  fit  so  as  to  slide  closely  in  holes 
bored  in  the  die  shoe  which  at  the  ends  is  cast  with  a  rectangular  boss  or 
projection  G  to  provide  sufficient  height  for  a  satisfactory  guide  for  the 
plungers  or  pins  F. 

The  casting  is  originally  made  with  portion  G  wide  enough  to  allow  the 
full  diameter  of  the  hole  to  be  bored  down  through  and  is  afterward  planed 
away  at  the  front,  as  indicated,  to  form  clearance  and  allow  the  plunger  to 
act  against  the  beveled  end  of  the  punch  slide  E. 

The  two  punch  slides  E,  E,  are  of  tool  steel,  hardened,  and  they  slide  in 
machine  steel  guides  H  which  are  secured  by  counter-sunk  head  screws  and 
dowel  pins  to  the  die  shoe.  The  slides  are  2J  in.  wide*  and  when  fitted 
to  their  horizontal  guides  they  are  prevented  from  lifting  by  cover  plates  1 
which  are  held  by  fillister  head  screws  to  the  guide  block.  The  cover 


90 


PUNCHES  AND  DIES 


plates  are  slotted  at  their  inner  ends  to  clear  the  tops  of  the  set  screws  for 
holding  the  piercing  punches. 

The  slides  with  their  punches  are  withdrawn  upon  the  upstroke  of  the 
press  by  means  of  the  compression  springs  JJ  which  are  located  upon 
studs  tapped  into  the  rear  of  the  slides  and  fitted  freely  in  holes  drilled 
horizontally  through  the  casting  at  G.  The  springs  act  against  the  washer 
and  nut  at  the  outer  end  of  the  studs  and  thus  force  the  studs  and  punch 
slides  outward  when  the  bevel  plungers  are  returned  to  their  upper  position. 

TOOLS  FOR  PIERCING  OBLIQUE  HOLES 

Following  along  to  other  special  forms  of  piercing  tools  we  come 
naturally  to  the  problem  of  piercing  holes  at  an  angle,  and  one  set  of  tools 
for  this  purpose  which  should  be  helpful  in  the  way  of  a  suggestion  for 
handling  various  jobs  of  similar  character  will  be  seen  in  Fig.  124. 


FIG.  124.  —  Dies  for  piercing  oblique  holes 

This  die  was  designed  to  pierce  two  |-in.  holes  at  an  angle  of  40  de- 
grees through  the  arc-shaped  piece  in  the  upper  corner  of  the  engraving. 
The  cast  steel  blank  holder  A  in  these  tools  is  suspended  from  the  cast  iron 
secondary  ram  B,  or  upper  member  of  the  dies,  by  the  guide  pins  C  which 
are  pressed  into  A  and  made  a  sliding  fit  in  B.  The  springs  /)  transmit 
power  for  the  blank  holder  A.  The  links  E  are  hinged  on  the  member  B 
and  on  the  punch*  operating  members  F,  which  in  turn  are  pivoted  in  the 
lugs  cast  integrally  with  the  blank  holder. 

The  punch  holders  G  which  are  a  sliding  fit  in  A  carry  the  two  piercing 


PIERCING  TOOLS— BLANKING  AND  PIERCING  DIES  91 

punches  H.  The  hardened  steel  pin  /  is  pressed  into  the  punch  holder  G 
and  serves  as  a  rest  for  the  forcing  device  F  which  is  cut  out  square  to 
allow  for  the  angular  movement  of  the  punch  holders.  The  button  dies  J 
are  pressed  into  the  cast  iron  base  K. 

The  drawing  shows  the  die  at  the  bottom  of  the  stroke.  The  die 
operates  as  follows :  The  blank  holder  A  and  the  secondary  ram  B  descend 
as  a  unit  until  the  blank  holder  strikes  the  piece  to  be  pierced,  holding  it 
securely  on  the  die.  The  secondary  ram  B  continues  its  downward  course, 
setting  the  toggle  arrangement  in  motion,  thus  piercing  the  holes.  On  the 
return  stroke  the  ram  B  ascends,  withdrawing  the  piercing  punches  and 
stripping  the  work.  The  blank  holder  remains  stationary  until  the  nuts  L 
bottom  in  the  counter-bored  holes.  The  ram  and  holder  then  ascend 
together. 


CHAPTER  IV 
COMPOUND  DIES  FOR  BLANKING  AND  PIERCING 

Compound  dies  combine  in  one  set  of  tools  located  about  the  same 
vertical  axis  or  center  line,  the  functions  of  two  distinct  classes  of  dies,  say 
piercing  and  blanking,  so  that  at  each  stroke  of  the  press  a  blank  is  cut  and 
one  or  more  holes  pierced  through  it  without  its  being  moved  except  as  it 
is  ejected  from  the  dies  upon  the  upstroke  of  the  machine.  This  arrange- 
ment is  therefore  entirely  different  from  the  progressive  or  follow  type  of 
die  where  piercing  of  the  stock  occurs  with  the  work  in  the  first  position 
in  the  tools  and  the  stock  is  then  advanced  to  the  second  position  for  the 
blanking  out  of  the  piece. 

The  compound  construction  means  that  the  piercing  punch  must  be 
located  inside  of  the  blanking  die  and  the  piercing  die  formed  inside  of  the 
blanking  punch.  There  are  occasions  where  work  is  blanked  and  drawn 
in  what  may  be  designated  as  compound  tools,  particularly  where  a  further 
operation  of  piercing  is  also  accomplished  at  the  same  time,  but  as  a  rule 
the  class  of  press  tools  used  for  blanking  and  drawing  or  for  blanking,  draw- 
ing, and  beading,  etc.,  in  a  single  stage  operation  in  a  single  action  press  are 
generally  known  as  combination  dies  which  are  fully  described  in  another 
chapter. 

COMPOUND  DIES  FOR  A  BRASS  DISK 

A  good  example  of  a  compound  die  and  punch  is  represented  by  the 
tools  in  Figs.  125,  126,  and  127.  These  were  made  for  producing  a  brass 
disk  IJ-in.  diameter  with  two  holes  pierced  0.10-in.  diameter  by  f-in. 
apart.  The  stock  used  is  ^Vin.  thick. 

The  blanking  punch  for  the  disk  is  shown  at  A,  Fig.  127,  the  blanking 
die  at  B,  the  piercing  punches  at  (7,  the  piercing  die  holes  at  D.  The 
blanking  punch  is  drilled  out  at  the  two  points  D  as  indicated  to  form  the 
piercing  die  openings;  the  blanking  die  B  carries  a  knock  out  or  ejector 
which  is  drilled  and  counterbored  from  the  rear  to  receive  the  two  piercing 
punches  C. 

The  blanking  die  measures  IJ-in.  diameter  across  the  body,  which  is 
shouldered  as  represented  to  correspond  to  the  internal  shoulder  of  clamp- 
ing ring  E.  This  ring  serves  to  house  in  all  members  of  the  lower  die  and 
acts  as  a  locating  medium  in  the  die  base,  in  that  it  is  fitted  into  a  shallow 

92 


COMPOUND  DIES   FOR  BLANKING  AND  PIERCING 


93 


seat  bored  into  the  face  of  the  base  and  is  there  located  and  secured  by  two 
dowel  pins  and  four  fillister  head  screws.  These  screws  are  tapped  in 
from  the  under  side  of  the  die  ring,  as  will  be  seen  from  the  photographic 
view  of  the  back  of  the  die  in  Fig.  126.  / 


FIG.  125.  —  Compound  die  for  blanking  and  piercing  a  small  disk 


FIG.  126.  —  Rubber  buffer  or  spring  on  compound  die" 

Blanking  die  B  rests  upon  the  chambered  ring  F  which  fits  the  bore  of 
the  retaining  ring  or  housing  E  and  which  is  recessed  out  to  a  diameter 
sufficient  to  receive  the  flanged  base  of  the  ejector  or  knock  out  G.  This 
is  a  nice  sliding  fit  in  the  die  and  it  serves  as  a  guide  for  the  slender  piercing 


94 


PUNCHES  AND  DIES 


0.010  Holes 


Brass 


punches  C.  The  latter  are  made  with  enlarged  bodies  and  heads  and  are 
secured  by  being  let  in  from  the  under  side  of  the  ring  F  which  is  counter- 
bored  to  conform  to  the  dimensions  of  the  heads  of  the  punches. 

OPERATION  OF  KNOCK  OUT 

The  knock  out  is  normally  held  in  uppermost  position  as  indicated  by 
the  pins  H  and  the  rubber  spring  /,  the  latter  being  retained  between  two 

steel  plates  and  the '  whole 
unit  of  rubber,  washers,  and 
carrying  stud  being  easily 
removable  at  any  time.  It 
is  the  practice  in  many  places 
to  make  one  or  two  of  these 
rubber  shedder  outfits  do 
duty  with  a  number  of  dif- 
ferent sets  of  dies  as  re- 
quired. The  device  is  at- 
The  Work  tached  to  any  set  going  into 

the  press  and  is  removed  and 
transferred  to  another  pair 
of  dies  when  the  first  job  is 
completed.  This  simplifies 
the  making  of  the  tools  in 
the  first  place  and  where  any 
given  set  of  dies  is  used  only 
occasionally  a  considerable 
measure  of  economy  is 
effected. 

While  the  dies  in  the 
views  referred  to  here  are 
shown  with  the  rubber  form 
of  spring,  such  tools  are  very 
commonly  made  with  steel 
compression  springs  of  vari- 


Spring 
Stop  Pin 


FIG.  127.  —  Details  of  compound  die 


ous  sections  which  are  used  for  operating  the  shedders  and  knock  outs. 
Some  die  makers  prefer  the  steel  spring  and  others  the  rubber.  Each  has 
advantages  and  very  often  the  question  of  limitation  of  space  in  the  tools 
or  press  determines  the  spring  medium  that  shall  be  employed. 

Where  space  is  available  it  is  desirable  to  make  the  ejector  pins  H  with 
small  heads  in  order  that  they  may  not  fall  out  when  the  rubber  or  spring 
device  at  the  bottom  is  removed. 


COMPOUND  DIES  FOR  BLANKING  AND  PIERCING  95 

BLANKING  PUNCH  DETAILS 

The  blanking  punch  A  is  secured  in  the  holder  J  and  is  enclosed  in  the 
shedder  ring  or  stripper  ring  K  which  is  normally  forced  down  to  the  lower 
position  shown  by  the  action  of  the  pressure  springs  on  the  fillister  head 
screws  L.  The  two  openings  constituting  the  piercing  dies  are  drilled  in 
the  blanking  punch  and  at  their  upper  ends  two  holes  are  drilled  in  at  an 
angle  to  form  a  passage  out  of  the  punch  for  the  slugs  as  pierced  out  of  the 
blank  by  punches  C  below. 

Two  guide  pins  for  the  strip  of  stock  are  located  at  M  and  a  stop  gage 
at  N,  as  seen  in  the  detail  sketch  below  the  die.  The  stop  N  is  spring 
actuated  and  when  the  punch  descends  the  combined  pressure  pad  for  the 
stock  and  stripper  K  forces  the  pin  downward.  The  blanking  punch  con- 
tinuing to  descend  blanks  out  the  disk  in  die  B  and  the  two  piercing  punches 
C  pierce  the  small  holes,  the  blanking  punch  forcing  the  shedder  G  down- 
ward against  the  action  of  the  rubber  below.  Upon  the  upstroke  the 
shedder  G  rises,  clearing  the  blanked  and  pierced  disk  from  the  blanking 


r 


PIG.  128.  —  Compound  piercing  FIG.  129.  —  Progressive  piercing 

and  blanking  dies  and  blanking  dies 

die  and  piercing  punches,  and  at  the  same  time  the  stripper  K  strips  the 
stock  from  the  blanking  punch  A. 

It  should  be  noted  that  the  small  die  holes  D  in  the  blanking  punch  are 
originally  drilled  and  reamed  all  the  way  through  the  blanking  punch  to 
enable  the  holes  to  be  taper  reamed  from  the  top  to  an  angle  of  2J  degrees 
for  clearance  for  the  slugs.  Afterward  the  tops  of  the  small  die  holes  are 
plugged  as  indicated  and  the  passage  of  the  slugs  deflected  by  the  side 
openings  at  an  angle  in  the  die.  The  punches  A  and  C  and  die  B  are  of 
tool  steel  hardened. 

A  CONTRAST  IN  CONSTRUCTION 

The  two  sets  of  dies  in  Figs.  128  and  129  are  shown  together  to  illus- 
trate the  differences  in  construction  in  the  open  progressive  die  in  the  latter 
view  and  the  compound  die  in  Fig.  128.  These  two  sets  of  tools  are  for 


96 


PUNCHES  AND  DIES 


practically  the  same  kind  and  size  of  work  and  form  good  subjects  for 
comparison. 

The  work  pierced  and  blanked  is,  in  each  instance,  about  4  in.  long 
by  1  in.  wide.  The  hole  pierced  is  f-in.  diameter.  The  features  of  the 
progressive  dies  at  the  right  in  Fig.  129  are  clearly  seen  and  require  little 


0 

O 

S 

/-'->          P 

I 

o  1 

0        0 

® 

The  Work 


T.S.Die 


0 


o 


FIG.  130.  —  Construction  of  compound  die 

explanation.  This  die  happens  to  have  a  long  stock  support  and  guide 
attached  at  the  right-hand  side  and  the  strip  of  metal  feeding  along  this 
member  is  first  pierced  with  the  punch  and  die  opening  at  the  side  of  the 
die  and  then  advances  to  the  next  position  where  it  is  blanked  at  the  same 
stroke  that  pierces  the  hole  in  the  stock  for  the  next  blank,  and  so  on. 
The  compound  die  in  Fig.  128  is  made  up  as  shown  by  the  drawing,  Fig. 


COMPOUND  DIES   FOR  BLANKING  AND  PIERCING  97 

130.  The  blanking  punch  A  is  here  inverted  and  carried  by  the  lower  shoe 
B  to  which  it  is  secured  by  fillister  head  screws  and  dowels.  It  is  provided 
with  a  spring  actuated  stripper  plate  C  which  is  forced  upward  by  the  com- 
pression springs  on  the  four  screws  D.  This  stripper  plate  carries  the  gage 
pins  for  locating  the  stock. 

The  piercing  die  is  formed  in  the  blanking  punch  and  the  piercing  punch 
E  and  blanking  die  F  are  carried  by  the  upper  head,  the  parts  being  secured 
as  shown.  The  blanking  die  is  provided  with  the  knock  out  G  which  is 
carried  by  the  spring  plunger  H.  The  work  blanked  is  quite  thin  and  the 
spring  knock  out  is  therefore  sufficiently  stiff  to  answer  the  purpose  for 
which  it  is  intended. 

It  will  be  seen  that  the  work  pierced  and  blanked  in  a  compound  die  of 
this  type  is  handled  under  several  advantages  as  compared  with  the  pro- 


FIG.  131.  —  Dies  for  thin  ring  or  washer 

gressive  type  of  tools.  In  the  first  place  the  blanking  and  piercing  being 
accomplished  simultaneously,  accuracy  of  the  hole  position  is  assured  in 
respect  to  the  edges  of  the  blank.  As  the  stock  is  held  between  the  pressure 
pad  and  the  face  of  the  die,  and  the  blank  as  produced  is  supported  by  the 
knock  out  in  the  die,  the  work  is  necessarily  kept  flat  and  free  from  wrinkles 
and  distortion.  The  piece  of  work  produced  in  the  dies  shown  is,  of  course, 
of  a  simple  character,  but  as  we  proceed  with  other  examples  of  compound 
die  work  we  shall  find  some  more  intricate  constructions. 

MAKING  A  THIN  STEEL  RING 

In  Fig.  131  a  set  of  tools  are  shown  for  making  a  steel  washer  of  light- 
gage  stock.  The  outside  diameter  of  the  work  is  3  in.,  the  hole  blanked 
out  at  the  center  is  2  in.  The  dies  are  of  the  compound  order  and  the 
details  of  the  different  parts  will  be  seen  in  Figs.  132  and  133. 

The  tool  steel  blanking  die  A  is  secured  in  the  cast  shoe  B  and  the  tool 


PUNCHES  AND  DIES 


FIG.  132.  —  Showing  details  of  tools  in  Fig.  131 


FIG.  133.  —  Sectional  view  of  the  dies  in  Fig.  131 


COMPOUND  DIES   FOR  BLANKING  AND  PIERCING 


99 


steel  piercing  punch  C  is  located  concentric  with  the  die  and  pressed  snugly 
into  place  in  its  seat.  The  ejector  ring  D  is  made  to  fit  in  the  annular 
space  between  the  die  and  punch  and  this  member  is  fitted  with  four 
operating  pins  E  whose  bodies  pass  down  through  the  base  and  rest  upon 
the  rubber  attachment  at  F  which  is  made  up  of  a  pair  of  J-in.  steel  plates 
with  the  rubber  section  between.  The  attachment  to  the  base  is  by  means 
of  the  f-in.  shouldered  stud  which  is  tapped  into  the  casting. 

The  blanking  punch  H  of  tool  steel  is  bored  out  to  form  the  piercing  die 
and  to  admit  the  knock  out  K  which  has  a  shank  passing  up  through  the 


ock  out  Bar 


Bolster 


Press  Base 


FIG.  134.  —  Application  of  positive  "knock  out" 

punch  holder  with  two  check  nuts  at  the  top.  For  light  stock  a  rubber 
spring  or  a  steel  coil  spring  at  /  may  be  made  to  serve  the  purpose  of  eject- 
ing the  center  as  punched  out  of  the  work  by  the  piercing  punch.  With 
the  extended  shank  on  the  knock  out  a  positive  action  may  be  secured  by 
the  top  of  the  shank  on  K  striking  a  stop  on  the  press  guide  when  the  ram 
ascends  to  the  top  of  its  stroke. 

POSITIVE  KNOCK  OUT 

One  form  of  positive  knock  out  is  that  shown  by  the  sketch,  Fig.  134. 
The  horizontal  bar  L  passed  through  a  slot  crosswise  of  the  press  slide  is 
suspended  by  springs  at  the  end  and  is  adapted  to  rest  with  its  upper  sur- 
face against  the  top  of  the  slot.  When  the  ram  is  near  the  top  of  its  stroke 
the  top  of  the  knock  out  bar  L  contacts  with  the  two  adjustable  stop 
screws  M  carried  by  the  press  guide  and  as  the  bar  L  can  then  travel  up- 


100 


PUNCHES  AND  DIES 


ward  no  further,  the  result  is  that  the  ram  continuing  upward  forces  the 
top  of  the  knock  out  plunger  N  against  bar  L  and  the  slug  is  ejected  from 
the  upper  die  0. 

A  SMALL  GEAR  WHEEL  JOB 

The  photograph,  Fig.  135,  illustrates  another  form  of  compound  die  as 
applied  to  the  blanking  and  piercing  of  a  small  nine-toothed  gear  which  is 
made  from  TV-in.  sheet  steel.  The  gear  is  TVin.  outside  diameter  and  the 
hole  at  the  center  is  J-in.  diameter. 

The  tools  are  of  the  subpressed  type  with  two  pillars  at  the  back  of  die 
shoe  and  punch  head.  The  details  of  construction  are  covered  in  the  line 
engraving,  Fig.  136. 


FIG.  135.  —  Compound  dies  for  making  a  small  gear 

The  blanking  punch  is  located  at  A  in  the  lower  member  of  the  set. 
The  hole  B  at  the  center  of  this  punch  for  the  piercing  die  is  relieved  a  short 
distance  below  the  top  as  seen  more  clearly  in  the  enlarged  detail  in  this 
engraving,  in  order  to  clear  the  slugs  more  freely.  The  punch  body  A  is 
let  into  the  cast  base  and  secured  by  screws  and  dowels.  It  is  fitted  with 
a  stripper  plate  C  which  is  made  to  the  same  tooth  outline  as  the  punch 
and  which  is  actuated  by  the  four  pressure  springs  beneath  at  D. 

The  blanking  die  E  is  inverted  and  carried  in  the  upper  member  of  the 
set  of  tools.  It  is  here  secured  in  the  same  manner  as  the  blanking  punch 
A  below  and  is  bored  out  to  receive  the  ejector  F  which  is  held  in  lower 
position  by  four  small  knock  out  pins  G  which  pass  up  through  the  head 
and  come  in  contact  with  the  spring  actuated  plunger  H  at  the  top. 


COMPOUND  DIES   FOR  BLANKING  AND  *  PIERCING'  ^,  -  101 


FIG.  136.  —  Compound  dies  for  making  a  small  gear 

ACTION  OF  THE  TOOLS 

The  piercing  punch  I  fits  through  the  center  hole  bored  in  the  ejector 
and  is  formed  with  a  shouldered  shank  fitted  in  the  head  as  indicated. 
When  the  press  slide  descends  the  gear  is  blanked  out  in  die  E  by  punch  A, 
and  at  the  same  time  piercing  punch  I  forms  the  center  hole  by  punching 
the  slug  into  the  piercing  die  in  punch  A.  When  the  dies  separate  by  the 
upstroke  of  the  press  stripper  C  clears  the  blanking  punch  A  of  the  stock 


102 


PUNCHES  AND   DIES 


scrap  and  the  knock  out  F  ejects  the  work  from  the  blanking  die  E.  The 
slug  from  the  piercing  operation  passes  down  through  the  die  opening  in  A. 
The  punches  and  dies  are  of  course  of  tool  steel  properly  hardened,  and 
the  knock  out  pins  G  are  of  drill  rod.  The  stripper  and  pressure  plate  C 
carries  the  stops  and  locating  pins  which  serve  as  a  gage  for  the  stock.  The 
die  E  at  the  top  is  counter-bored  at  two  points  on  the  center  line  to  provide 
clearance  openings  for  the  gear  blank  as  carried  along  through  the  dies  by 
the  movement  of  the  strip  of  stock  as  it  is  fed  forward  for  the  production 
of  successive  gears.  The  gear  as  produced  and  knocked  out  of  the  blank- 
ing die  is  forced  back  into  its  place  in  the  scrap  by  the  action  of  the  ejector 
or  knock  out  F  and  is  thus  carried  along  with  the  material  as  it  feeds  along 
between  the  dies. 


FIG.  137.  —  Dies  for  thin  washer  with  keyway  punched  out 

The  special  feature  of  dies  of  this  character,  where  the  work  is  ejected 
by  the  process  shown  and  forced  back  into  the  opening  in  the  scrap,  has 
led  to  their  being  called  in  some  places  "  cut-and-carry "  dies. 

WASHER  AND  KEY  SLOT  DIES 

In  general,  the  compound  tools  in  Figs.  137  and  138  are  quite  similar 
to  the  washer  dies  in  Fig.  131.  There  is  however  an  interesting  point  of 
difference  in  that  the  dies  in  the  former  views  are  for  making  a  thin  washer 
or  ring  in  which  a  key  slot  is  pierced  at  the  same  time  that  the  outside  is 
blanked  and  the  center  punched  out. 

The  view  in  Fig.  138  of  the  tools  taken  apart  shows  all  of  the  members 
clearly  and  it  is  unnecessary  here  to  enter  into  a  prolonged  description. 
It  may  be  pointed  out  that  the  blanking  punch  and  die  and  the  piercing 
punch  are  held  and  located  in  their  respective  seats  in  the  same  manner  as 
the  corresponding  tools  referred  to  in  connection  with  the  set  of  dies  in 


COMPOUND  DIES   FOR  BLANKING  AND  PIERCING 


103 


Fig.  131.  But  the  piercing  punch  is  made  up  with  the  square  extension 
at  one  side  for  producing  the  key  way  cut  and  similarly  the  interior  of  the 
blanking  die  is  cut  out  for  a  key  slot  to  correspond.  Also  the  knock  out 
for  both  tools  is  made  with  the  key  slot  in  the  blanking  die  ejector  and  with 
the  key  extension  on  the  side  of  the  knock  out  in  the  piercing  die. 

The  shedder  springs  and  the  rubber  knock  out  device  for  the  lower 
die  are  identical  with  the  others  already  described.  There  is  one  further 
feature  that  should  be  noted  here  and  it  applies  to  the  dies  in  Fig.  131  as 
well.  This  is  the  set  of  disks  seen  at  the  right  of  the  stripper  plate  which 
are  adapted  to  fit  into  the  counter-bored  seats  for  the  ends  of  the  com- 
pression springs  which  operate  the  stripper  on  the  blanking  punch.  These 
disks  are  J-in.  thick  and  their  purpose  is  to  diminish  the  depth  of  the 


FIG.  138.  —  Showing  construction  of  dies  in  Fig.  137 

spring  seats  by  that  amount  when  the  dies  are  new.  After  repeated  grind- 
ings  have  shortened  the  dies. by  about  the  same  degree  or  J  in.  and  the 
stripper  has  been  adjusted  accordingly,  the  disks  are  removed  so  that  the 
springs  then  have  practically  the  same  distance  between  their  opposing 
seats  as  they  had  at  the  outset,  thus  keeping  a  fairly  uniform  tension  during 
the  continued  use  of  the  dies. 

These  packing  disks  are  shown  in  place  in  the  sectional  view  of  the 
other  set  of  tools  in  Fig.  133  where  they  are  designated  by  the  letter  X. 

LARGER  COMPOUND  TOOLS 

Still  another  interesting  set  of  compound  dies  is  shown  by  Figs.  139  and 
140.  These  are  for  making  a  disk  of  steel  plate  about  TV-in.  thick,  having  a 
large  V-gap  cut  at  one  side  and  two  rivet  holes  pierced  along  each  edge  of 
the  gap.  The  center  is  punched  out  at  the  same  time.  General  propor- 


104 


PUNCHES  AND  DIES 


tions  of  the  work  are  indicated  in  Fig.  141  and  a  good  idea  of  the  principle 
features  of  the  dies  themselves  is  presented  by  the  plan  and  sectional  views 
in  Figs.  142  and  143. 

The  work  is  a  circular  blank  about  6  in.  across  and  the  V  at  the  side 
is  about  30  degrees  included  angle.  The  piece  is  seen  to  the  left  of  the 
group  of  die  parts  in  Fig.  140.  The  blanking  die  is  shown  at  A  and  the 


.  139.  —  Another  example  of  compound  die  work 


FIG.  140.  —  The  dies  taken  apart 

blanking  punch  at  B.  The  blanking  die  head  is  bored  at  the  center  for  a 
seat  for  the  piercing  punch  C  and  both  the  punch  and  the  internal  wall  of 
the  blanking  die  are  slotted  as  indicated  at  D  to  receive  the  ends  of  the  in- 
serted piece  D  which  blanks  out  the  V-shaped  opening  in  the  disk. 

The  blanking  punch  is  bored  and  ground  out  at  the  center  for  a  2-in. 
hole  E  to  form  the  piercing  die.  The  punches  and  the  die  are  of  tool  steel 
carefully  hardened  and  finished  and  secured  by  fillister  head  screws  and 
dowel  pins  to  their  respective  holders. 


COMPOUND  DIES   FOR  BLANKING  AND  PIERCING 


105 


FIG  142 
FIGS.  141-143.  —  Construction  of  dies  shown  in  Fig.  139 

STRIPPER  AND  KNOCK  OUT 

The  stripper  and  pressure  pad  which  encloses  the  blanking  punch  B  is 
operated  as  at  F  against  a  thick  rubber  ring  G  which  is  seated  in  a  large 
recess  faced  out  in  the  shoe  H.  A  series  of  fillister  head  screws  passing  up 
through  the  ring  and  into  the  stripper  retain  the  latter  in  position. 

The  knock  out  disk  7  for  the  blanking  die  is  held  by  screws  from  the  top 


106  PUNCHES  AND   DIES 

of  the  head  and  is  actuated  by  a  series  of  stiff  springs  to  eject  the  work  from 
the  die  when  the  latter  rises  from  the  punch.  The  four  small  rivet  hole 
piercing  punches  JJ  are  inserted  in  blocks  which  are  fastened  by  screws 
and  dowels  in  the  interior  of  the  blanking  die  as  seen  in  the  drawing.  These 
small  punches  and  their  holding  blocks  are  also  shown  in  place  in  the  die  in 
Fig.  140. 

The  die  holes  for  the  piercing  of  the  small  holes  are  shown  at  KK,  Fig. 
142,  and  the  corresponding  holes  in  the  knock  out  I  are  plainly  visible  in 
the  photograph,  Fig.  140. 

Both  the  stripper  F  and  the  knock  out  I  are  shown  by  detail  sketches 
in  Fig.  143.  The  central  portion  of  the  stripper  is  attached  to  the  main 


FIG.  144.  —  Large  compound  dies  for  blanking  and  piercing  a  rectangular  plate 

ring  by  a  narrow  tongue  as  indicated,  following,  of  course,  the  outline  of  the 
piercing  punch  at  this  point.  The  projecting  portion  of  the  stripper  is 
therefore  provided  with  a  separate  rubber  spring  at  L  and  a  fillister  head 
screw  is  tapped  in  from  the  under  side  as  with  the  other  portions  of  the 
stripper  ring. 

A  RECTANGULAK  PIECE  OF  WORK 

Another  large  compound  die  is  represented  by  Fig.  144.  The  tools 
here  are  for  producing  the  steel  plate  in  Fig.  145  which  is  afterward  bent 
and  formed  to  the/  shape  in  Fig.  146  for  a  casing  for  certain  mechanism  of  a 
coin  register.  The  stock  is  jVin-  thick  and  the  piece  is  cut  out  approxi- 
mately to  length  and  width  before  it  is  placed  in  the  compound  dies  for 
trimming  to  correct  shape  and  piercing  of  the  various  holes. 

There  are  a  number  of  different  sizes  of  holes  among  the  number  pierced 
and  some  of  them  are  rectangular  for  the  staking  in  of  other  members.  The 
largest  round  holes  are  1.082-in.  diameter,  the  smallest  0.125  in.  Four 
small  tongues  are  formed  along  one  edge  in  these  dies  and  the  4|-in.  gap 
at  the  front  is  also  cut  out. 

The  half-tone  engraving  of  the  tools  gives  a  pretty  clear  conception  of 


COMPOUND  DIES   FOR  BLANKING  AND  PIERCING 


107 


the  maiuier  in  which  the  dies  are  made  up.  They  are  of  sectional  con- 
struction, the  blanking  die  A  being  built  up  of  tool  steel  sections  let  into 
channels  planed  in  the  base  and  there  held  by  fillister  head  screws  and 
dowels.  The  piercing  punches  are  inserted  into  place  in  the  die  base  and 
the  larger  ones  held  by  a  screw  from  the  bottom.  The  smaller  ones  are 
pressed  into  their  holes. 


The  Piece  as  it  comes 
from  the  Dies 


.078 


FIG.  146 

The  Work. 

after  Bending 


FIGS.  145-146.  —  The  work  blanked  and  pierced  in  large  compound  die 

The  blanking  punch  with  its  openings  constituting  the  piercing  dies  is 
seen  at  B.  This  member  is  also  sectional  and  the  locations  of  holding 
screws  and  dowel  pins  will  be  noticed  in  the  view.  The  stripper  for  the 
punch  is  shown  immediately  in  the  front  of  that  member  and  the  knock  out 
for  the  blanking  die  A  is  likewise  seen  in  front  of  the  die  base.  Both  knock 
out  and  stripper  are  bottom  side  up  in  order  that  the  provision  for  operating 
springs  may  be  visible. 

For  the  die  knock  out  there  are  15  of  these  springs,  for  the  punch  stripper 
there  are  12  in  all.  The  seats  for  the  ends  of  the  springs  are  neatly  formed 
by  hollow  milling  in  a  series  of  annular  channels  which  are  f-in.  deep  and 
of  the  proper  diameter  outside  and  inside  to  accommodate  the  spring  di- 
mensions. This  gives  a  form  of  spring  seat  that  holds  the  spring  without 
possibility  of  its  tilting  and  thus  maintains  it  in  most  effective  position  at 
all  times. 

The  underside  of  the  stripper  is  shown  fitted  with  four  flat  springs. 


108 


PUNCHES  AND  DIES 


These  act  upon  the  lower  ends  of  a  set  of  gage  pins  or  stops  which  normally 
extend  up  through  the  face  of  the  stripper  and  form  setting  stops  for  the 
work.  Upon  the  punch  passing  down  into  the  work  the  spring  pins  are 
depressed  accordingly  and  rise  to  original  position  when  the  punch  again 
ascends. 

ELECTRICAL  WORK  DIES 

One  of  the  most  common  uses  of  the  compound  die  is  in  connection 
with  the  blanking  and  piercing  of  parts  for  electrical  apparatus,  and  a  set 

of  tools  of  this  nature  are  shown 
by  the  engraving,  Fig.  147. 

These  dies  are  for  armature 
disks  and  this  is  an  example  of 
the  advantages  of  such  tools 
in  producing  perfect  concen- 
tric work  which  is  essential 
with  this  class  of  material. 
The  dies  produce  a  disk  with 
32  notches  and  the  close  fitting 
stripper  ring  for  the  punch  is 
controlled  by  the  same  number 
of  springs,  which,  with  the 
guide  pins,  are  clearly  repre- 
sented in  the  lower  member  of 
FIG.  147.  —  Armature  disk  punch  and  die 

the  set. 

Dies  of  this  type  are  employed  for  making  various  designs  of  disks, 
some  with  external  notches,  others  with  notches  inside.  Figs.  148,  149 
and  150  show  three  forms  of  such  rings  or  disks  as  commonly  blanked  and 


FIG.  148  FIG.  149  FIG.  150 

FIGS.  148-150.  —  Methods  of  notching  disks  for  electrical  machinery 

pierced.  Electrical  work,  like  typewriter  manufacture,  adding  machine 
and  calculating  machine  work  and  so  on,  requires  extensive  application  of 
many  interesting  forms  of  dies  and  certain  examples  of  compound  as  well 
as  plain  dies  for  these  lines  of  manufacture  will  be  referred  to  on  other 
pages. 


COMPOUND  DIES   FOR  BLANKING  AND  PIERCING 


109 


•Punch  Shoe 


A  STATOR  PUNCHING  DIE 

It  may  be  of  interest  here  to  show  a  compound  die  for  a  stator  punching 
which  is  a  typical  form  used  by  one  of  the  largest  manufacturers  of  electri- 
cal equipment.  The  sketch,  Fig.  151,  gives  an  outside  and  part  interior 
view  of  such  a  die  with  the  parts  designated  by  name. 

The  tool  steel  die  ring  is  secured  to  the  upper  half  of  the  tools  and 
blanks  out  the  work.  The  lower  half  serves  as  the^  blanking  die.  It 
has  a  stripper  plate  resting  on  springs  and  this  removes  the  material 
outside  of  the  punching,  that  is  the  corners  and  margin.  The  punches 
for  the  slots  are  set  into  the  upper  die  plate  and  there  is  also  a  guide 
plate  that  serves  to  hold  the 
punches  in  position  instead 
of  leaving  them  supported 
at  the  ends  only.  In  back 
of  the  punch  shoe  there  is 
a  member  known  as  a 
knocker  plate  which  is  set 
into  a  recess  with  sufficient 
clearance  to  allow  of  sliding 
along  the  axis  up  and  down. 
This  plate  is  connected  with 
the  upper  stripper  plate  or 
knock  out  by  screws  and 
knock  out  pins.  In  opera- 
tion, after  the  stator  punch- 
ing has  been  made  and  the 


FIG.  151.  —  Compound  dies  for  stator  punchings 


upjper  die  rises,  the  outer  scrap,  of 'course,  is  lifted  by  the  stripper  on  the 
lower  punch,  the  tooth  scrap  falling  through  the  lower  openings  and  the 
punching  being  carried  up  by  the  upper  die  until,  when  the  latter  is  near 
the  top  of  its  travel,  a  stationary  pin  strikes  the  knock  out  plate  and  re- 
leases the  punching. 

It  is  customary  with  these  tools  to  harden  the  die  in  all  cases  but  to 
leave  the  punch  soft  for  dies  on  such  punchings  as  just  shown,  to  facilitate 
upkeep  and  repair. 

LIMITS  IN  VARIATION 

The  accuracy  with  which  such  dies  are  made  and  set  up  in  the  press 
has  much  to  do  with  the  amount  of  burr  found  on  the  work  and  it  is  de- 
sirable that  definite  standards  as  to  the  amount  of  variation  permissible 
should  be  fixed  upon  and  the  tools  then  held  accordingly.  The  limits 
established  by  the  firm  referred  to  and  to  which  punches  and  dies  are  held, 
are  as  follows  for  stator  and  rotor  punchings:  small  round  hole  dies  are  to 
be  kept  within  plus  and  minus  0.002  in.;  larger  round  hole  dies  within 


110 


PUNCHES  AND   DIES 


plus  and  minus  0.003  in.  Allowance  for  outside  diameter  of  ordinary 
punchings  made  with  round  hole  dies  from  6  to  12-in.  diameter  is  —0.004 
to  +0.006  in.;  for  12-in.  diameter  and  up  -0.005  in.  to  +0.006  in.  For 
rotor  and  stator  punchings  made  with  compound  dies  the  following  limits 
are  allowed:  From 


1  to  15  in., 
15  to  20  " 
20  to  25  " 
25  to  35  " 


+0.002  in.  to  -0.004  in. 
+0.002    "    "   -0.005  j" 
+0.003    "    "   -0.005  " 
+0.004    "    "   -0.006  " 


The  allowance  on  the  bore  for  rotor  punchings,  shaft  fits,  is  between 
1-0.001  and  —0.003  in.  for  all  diameters  of  bore.  For  pole  punchings 

on  direct-current  machines 
the  variation  in  height,  that 
is  the  difference  between 
inside  and  outside  radius  on 
the  individual  punching,  is 
allowed  to  be  +0.003  in. 
to  -0.002  in.  for  1  in.  to 
4  in.  high,  and  +0.005  to 
-0.002  in.  for  4  in.  and 
above. 

A  SPECIAL  FORM  OF  KNOCK 
OUT  BUSHING 

One  more  example  of 
compound  die  design  is 
included  here.  This  is  a 
set  of  tools  for  making  a 
lock  washer  from  J-in.  steel 
scrap.  One  of  the  features 
of  the  die  is  the  knock  out 
bushing  A,  Fig.  152.  This 
bushing  is  shown  to  larger 
scale  in  the  detail  at  the 
lower  corner  of  the  engrav- 
ing. The  bushing  is  so  made  that  it  is  impossible  to  plug  up  the  die  as 
long  as  the  operator  gives  attention  to  his  work. 

The  knock  out  bushing  has  a  series  of  holes  X  drilled  in  its  face  and 
these  are  known  as  "signal  holes"  for  they  will  always  show  whether  the 
last  blank  has  been  discharged  or  not.  Should  a  washer  stick  in  the  die 
and  cover  the  signal  holes,  the  difference  between  the  plain  face  of  the 


FIG.  152.  —  Lock  washer  tools 


COMPOUND  DIES   FOR  BLANKING  AND  PIERCING  111 

washer  and  the  drilled  face  of  die  A  at  once  becomes  apparent  to  the 
operator  who  can  then  remove  it  before  tripping  the  press. 

The  punch  shoe  B  is  of  cast  iron  and  fits  the  press  ram  to  which  it  is 
bolted.  The  die  base  D  is  made  of  cast  iron  and  aligned  with  the  punch 
by  the  steel  guide  pins  E  and  bushings  F.  The  blanking  punch  G  is  of 
hardened  tool  steel.  This  punch  is  counter-bored  above  the  piercing  open- 
ing for  slug  clearance  and  has  an  opening  at  H  through  which  the  slugs  are 
discharged  into  the  chute  7,  which  is  fastened  to  the  punch  shoe  by  the 
screw  L  and  so  arranged  that  the  slugs  will  fall  clear  of  the  die.  The  punch 
is  held  by  the  screw  /  and  kept  from  turning  by  a  tapered  pin  at  K. 

The  blanking  die  is  a  bushing  held  in  place  by  the  threaded  bushing  M 
which  is  seated  and  secured  by  a  spanner  wrench  fitted  to  holes  N.  The 
stripper  0  held  by  cap  screws  P  is  open  in  front  to  allow  the  operator 
greater  freedom  and  better  view  while  using  the  die.  The  opening  under 
the  stripper  at  R  is  necessary  in  order  to  let  the  washer  slide  off  the  die 
when  blanked,  the  press  being  inclined  at  an  angle  of  45  degrees. 

The  bushing  A  is  made  of  tool  steel  hardened  and  ground  to  size  and 
serves  as  a  knockout  for  the  blanking  die.  Special  care  must  be  taken  at 
the  time  of  setting  up  the  die  to  get  the  proper  pressure  on  the  pad  A  by 
the  correct  adjustment  and  tension  of  the  spring  S  and  the  nuts  T. 

The  pressure  is  transmitted  to  the  knock-out  bushing  by  the  plate  U 
under  the  die  and  the  hardened  pins  V.  The  perforating  punch  W  has  a 
square  head  to  prevent  it  from  turning  in  the  die  and  is  securely  seated 
by  set  screws  Y.  The  die  is  fastened 'to  the  bed  of  the  press  by  the  cap 
screws  Z. 


CHAPTER  V 


CUTTING-OFF  DIES  OR  PARTING  TOOLS 

In  addition  to  the  blanking  processes  already  illustrated  in  preceding 
chapters,  there  is  another  method  by  which  blanks  are  produced  which  may 
well  be  described  before  the  subjects  of  trimming  and  shaving  dies  are 
taken  up.  This  method  makes  use  of  one  of  the  simplest  forms  of  press 
tools,  the  cutting  off  or  parting  die,  sometimes  known  as  a  shearing  die, 
as  in  its  primary  form  it  is  merely  a  set  of  tools  with  a  straight  cutting  off 
punch  shearing  past  a  similar  die  as  in  Fig.  14,  Chapter  I. 

With  the  cutting  off  or  parting  die  the  strip  of  material  operated  upon 
is  of  the  width  wanted  for  the  work  and  the  production  of  the  blank  con- 
sists in  cutting  the  stock  to  the  requisite  length,  this  length  being  gaged 
by  a  stop  set  as  in  the  case  of  various  other  types  of  dies. 

The  cutting  off  tool  is  not  necessarily  confined  to  simple  shearing  of  a 
straight  edge  across  the  piece,  for  it  is  quite  as  adaptable  to  the  cutting  of  a 


FIG.  153.  —  A  piercing  and  cutting-off  die 

curved  end  or  other  form  for  the  work  and  in  fact  is  extensively  employed 
on  pieces  of  this  sort.  Furthermore  it  is  often  combined  with  piercing  and 
other  tools  to  sever  the  blank  from  the  end  of  the  strip  of  metal  after  other 
operations  have  been  accomplished  in  dies  of  the  progressive  or  follow  type. 

PIERCING  AND  CUTTING-OFF  ARRANGEMENT 

A  set  of  tools  of  this  character  for  piercing  several  holes  in  the  material 
and  cutting  to  length  are  shown  by  Figs.  153  and  154.  The  blank  made  is 
in  this  instance  4  in.  long  by  2|  wide  with  five  J-in.  holes  spaced  as  rep- 
resented and  a  IJ-in.  hole  punched  near  the  center.  The  material  is 
cold  rolled  steel. 

112 


CUTTING-OFF  DIES  OR  PARTING  TOOLS 


113 


The  photograph  and  drawing  show  most  of  the  tool  details  clearly  and 
a  brief  explanation  will  answer  all  purposes.  The  stock  is  the  width  re- 
quired for  the  work  and  the  strip  of  metal  is  held  true  against  the  guide  at 
the  back  of  the  die  by  the  projecting  handle  of  the  bent  member  A  which 


FIG.  154.  —  Piercing  and  cutting-off  dies 

forces  the  work  squarely  against  the  guide  B.  The  method  of  locating 
the  different  punches  for  piercing  and  the  cutting-off  punch  C  will  be 
seen  from  the  drawing. 

The  cutting-off  punch  is,  in  this  case,  shown  with  a  relieved  or  backed 
off  edge  of  about  8  degrees  to  give  freedom  of  cut  and  it  might  with  equal 


114 


PUNCHES  AND   DIES 


ease  be  made  with  a  sheared  edge  from  front  to  back  if  the  metal  operated 
upon  were  sufficiently  heavy  to  necessitate  it. 

The  end  of  the  stock,  as  it  is  passed  through  the  stripper,  is  first  trimmed 
off  by  the  cut-off  punch  and  the  strip  of  metal  is  then  advanced  against 


DETAIL  OF  DIE 
TO  ENLARGED 


FIG.  155.  —  Cut-off  dies  for  round  ends 

the  stop  D  for  cutting  off  to  length.  The  first  down  stroke  of  the  punch 
has  already  pierced  the  work  and  the  first  cut-off  or  trimming  of  the  end 
prepares  the  leading  end  so  that  each  following  down  stroke  pierces  the 
holes  through  the  material  while  the  preceding  blank  is  severed  by  cut-off 
punch  C. 

There  are  numerous  combinations  of  piercing  punches  and  parting 


CUTTING-OFF  DIES  OR  PARTING  TOOLS 


115 


tools  on  work  of  this  general  character  and  various  methods  of  securing 
the  punches  to  the  holder.  The  method  illustrated  is  only  one  of  several 
satisfactory  ways  in  which  they  may  be  inserted  and  fastened  in  place. 

END-FOEMING  PARTING  TOOLS 

The  dies  in  Fig.  155  represent  an  example  of  a  set  of  cutting-off  dies 
which  at  one  stroke  pierce  holes  in  the  ends  for  adjoining  blanks  and  cut 
the  two  pieces  apart,  at  the  same  time  shaping  the  ends  to  the  round  form 
F,  shown  at  the  upper  corner  of  the  drawing.  The  tools  are  arranged  with 
a  centrally  located  cutting-off  punch  and  a  piercing  punch  at  either  side. 

As  indicated  at  G,  the  central  punch  is  in  the  form  of  a  concave  sided 
tool  with  section  suited  to  the  curves  required  on  the  ends  of  the  pieces  to 
be  cut  off  from  the  strip  of  stock.  The  material  worked  is  1^-in.  wide 
and  the  punch  is  TV  more  or  1T9^  in.  from  front  to  back.  The  piercing 
punches  are  located  to  pierce  a  ^-in.  hole  at  each  side  of  the  parting  punch. 


FIG.  156.  —  Slotting  and  cutting-off  tools. 

The  strip  of  material  to  be  used  for  the  work  is  fed  past  the  edge  of  the 
cut-off  punch  G  and  the  first  stroke  shapes  the  leading  end  of  the  work  and 
pierces  the  hole  in  that  end.  Then  the  work  is  advanced  to  the  gage  H 
and  the  next  stroke  of  the  slide  causes  the  punch  /  to  pierce  the  second  end 
of  the  first  piece  while  the  punch  G  cuts  it  off  and  shapes  the  end  of  the 
next  piece  and  the  punch  J  pierces  the  ^-in.  hole  for  that  piece.  So  for 
each  succeeding  operation  of  the  punch  a  piece  is  completed  and  cut  off. 

The  dies  KK  are  inserted,  as  they  are  of  the  button  type,  and  each  is 
finished  to  a  diameter  of  l^V  in.  with  the  front  edge  at  L  ground  to  the 
longer  radius  required  or  ||  in.  This  facing  of  the  die  to  the  radius 
given  at  the  point  of  cutting  only,  makes  it  possible  to  use  a  smaller  diam- 
eter of  body  for  the  die  and  when  the  cutting  portion  becomes  worn  the  die 
'may  be  pressed  out  of  its  seat,  a  new  portion  of  the  edge  ground  to  the 
radius  of  $f  inch  and  the  die  pressed  back  into  new  position  for  continued 
service. 


116 


PUNCHES  AND  DIES 


A  SLOTTING  AND  CUTTING-OFF  JOB 

The  tools  in  Figs.  156  and  157  are  for  a  somewhat  similar  piece  of  work 
to  that  just  shown  except  that  the  work  in  Fig.  157  has  a  slot  pierced  in  each 
end  besides  the  round  hole  pierced  at  one  end  only.  The  ends  are  cut  off 
square  and  the  work  measures  7  in.  in  length.  It  is  cut  off  from  TV -in.  steel 
£-in.  wide. 

The  punches  are  placed  as  represented  in  the  plan  and  side  views.    The 


FIG.  157.  —  Slotting  and  cutting-off  tools 

slotting  punches  are  sheared  along  the  edge  to  give  free  cutting  action  in 
piercing  out  the  rectangular  opening.  They  are  placed  If  in.  apart  on 
centers,  and  the  cut-off  punch  is  located  midway  between. 

The  work  is  produced  as  indicated  by  the  plan  view  of  the  die  proper. 
The  stock  is  first  advanced  past  the  cut-off  punch  which  shears  off  the  end 
of  the  strip  and  the  round  hole  A  and  slot  B  are  pierced  at  the  same  stroke. 
Then  the  work  is  fed  along  to  the  stop  C  and  the  next  down  stroke  of  the 


CUTTING^OFF  DIES  OR  PARTING  TOOLS  117 

press  pierces  the  slot  D  at  the  opposite  end  of  the  piece  and  also  cuts  the 
piece  off  at  E  and  pierces  hole  A'  and  slot  B'  in  the  next  length  at  the  same 
time.  So  each  following  stroke  of  the  press  completes  a  piece. 

The  stock  guide  under  the  stripper  holds  the  stock  closely  sidewise  and 
assures  its  being  pierced  and  severed  squarely  without  twisting  to  one  side. 

PARTING  TOOLS  FOR  A  GERMAN  SILVER  BAR 

The  set  of  dies  in  Figs.  158  and  159  are  for  cutting  off  german  silver  bars 
to  form  the  decimal  pointer  bar  used  on  a  calculating  machine.  One  of 
these  pieces  will  be  seen  in  front  of  the  dies  in  Fig.  158  and  detail  dimen- 
sions are  given  in  Fig.  160.  The  material  from  which  the  bars  are  cut  off 
is  0.140-in.  wide  and  0.078-in.  thick.  The  ends  are  formed  to  a  true 


-- 


FIG.  158.  —  Parting  and  end-forming  dies 

half  circle  in  the  cutting-off  process.  The  three  small  holes  in  the  bar  are 
afterward  drilled  and  counter-sunk  as  shown. 

The  punch  is  in  the  form  of  a  letter  "H"  as  shown  at  A,  Fig.  159, 
finished  on  the  end  of  a  square  shank  with  broad  base  B  secured  by  two 
fillister  head  screws  and  dowels  to  the  head.  This  punch  fits  closely 
through  an  opening  in  the  pressure  pad  C  and  the  lower  end  of  the  punch 
is  guided  in  the  oblong  die  openings,  while  the  central  or  cutting  portion  of 
the  punch  at  D  cuts  the  work  apart  and  produces  the  rounded  ends  on  the 
material.  The  small  slug  punched  out  to  sever  the  work  is  forced  down 
through  the  central  die  opening  at  E  in  the  same  manner  as  a  slug  from  a 
piercing  operation. 

The  narrow  bar  to  be  cut  off  is  placed  in  the  slot  in  the  guide  at  the  top 
of  the  die,  this  guide  extending  to  the  left  as  in  Fig.  158  to  support  the  pro- 
jecting work  and  act  as  an  end  stop  for  determining  the  length  cut  off. 
This  guide  is  attached  to  the  die  by  two  counter-sunk  head  screws  and  its 
position  is  maintained  by  these  screws  and  by  a  pair  of  small  dowel  pins. 


118 


PUNCHES  AND   DIES 


The  die  itself  is  attached  to  its  base  by  four  fillister  head  screws  tapped 
in  at  the  corners  from  the  bottom  and  two  dowels  are  located  at  diagonally 
opposite  positions  as  seen  in  the  photograph 
The  pressure  pad  is  formed  with  a  central  ledge  or  projection  at  F  which 


No.42  Holes  C.Slnk     Dccimal  Pointer  BM[ 
German  Silver 


FIGS.  159-160.  —  Details  of  parting  dies  shown  in  Fig.  158 


FIG.  161.  —  Progressive  piercing,  forming,  and  cutting  off  dies 

bears  directly  upon  the  narrow  strip  of  work  during  the  cutting-off  opera- 
tion. This  bearing  surface  extends  the  full  width  of  the  die  face  or  3£ 
in.,  except  for  the  one-eighth  portion  at  the  center  which  is  cut  out  to 
clear  the  cutting  portion  of  the  punch. 


CUTTING-OFF   DIES  OR  PARTING  TOOLS 


119 


PIERCING,  FORMING,  AND  CUTTING  OFF    . 

The  half  tone,  Fig.  161,  illustrates  a  set  of  dies  of  the  progressive  order, 
for  piercing,  forming  the  lugs,  and  cutting  off  the  piece  shown  in  the  fore- 
ground of  the  photograph.  As  represented  the  completed  piece  is  shown 
resting  in  contact  with  a  strip  of  metal  pierced  and  formed  for  the  lugs  anc( 
ready  for  cutting  off. 

The  tools  are  shown,  also,  in  the  line  drawing,  Fig.  162,  and  the  work 
itself  in  Fig.  163.  From  the  latter  sketch  it  will  be  seen  that  the  strip  of 
steel  is  first  pierced  for  the  t wo  holes  A,  A,  which  are  J-in.  ^diameter  and 


>2 


VCV  *    VJ '  LJ-^X'  21  '/  '  1    ''  • 


FIG.  162 
FIGS.  162-164.  —  Piercing,  forming  and  cutting-off  tools 

1TV  in.  apart  on  centers;  then  the  stock  advances  in  the  dies  and  the  two 
lugs  or  ears  B,  B  are  formed  by  a  pair  of  piercing  and  bending  punches 
and  at  the  same  time  the  triangular  point  C  is  formed  down  and  the  corre- 
sponding point  on  the  preceding  piece  formed  at  D.  The  third  position 
of  the  work  brings  it  into  place  for  cutting  off. 

The  order  of  operations  is  very  clearly  indicated  in  the  sectional  view, 
Fig.  164,  where  the  two  piercing  punches  are  shown  at  A  'A'  for  the  |-in. 
holes;  the  two  cutting  and  forming  punches  at  B'B'  for  the  lugs  or  ears  B; 
the  bending  punches  at  C"  for  the  pointed  ears  C  and  D;  the  cutting-off 
punch  at  E'  for  severing  the  finished  work. 

The  sectional  views  and  plans  in  Fig.  162  show  most  of  the  important 


120  PUNCHES  AND   DIES 

dimensions  and  the  method  of  placing  punches  and  other  details.  The 
punches  B'B'  for  cutting  and  bending  down  the  projections  or  ears  B  are 
sheared  or  beveled  from  the  rounded  edge  back  to  the  heel  so  that  the  cut 
will  be  started  at  the  semi-circular  end  of  the  ear,  and  the  width  of  the 
punch  back  from  this  edge  to  the  heel  is  ^  in.  under  the  dimension  for  the 
die  or  a  difference  equal  to  the  thickness  of  the  stock,  so  that  the  punch  will 
have  a  bending  action  on  the  work  and  carry  the  material  down  over  the 
corner  as  at  B  2  and  thus  form  up  the  lug  as  indicated.  The  punches  B'B' 
are  provided  with  pilots  to  center  the  work  from  the  two  pierced  holes  put 
through  by  punches  A' A'. 

The  punches  C'D'  are  sheared  to  cut  from  opposite  corners  to  start  the 
cut  on  the  triangular  points  C  and  as  they  have  the  same  clearance  of  ^V 
in.  between  the  back  of  the  punch  and  the  edge  of  the  die  they  bend  the 
point  down  in  the  manner  shown. 

The  hole  at  H  is  a  clearance  space  for  the  ears  BB  after  these  are  formed 
and  the  material  fed  along  for  the  next  cut.  The  view  in  Fig.  164  shows 
the  two  projecting  portions  extending  down  into  this  opening.  At  the 
same  time  the  two  triangular  points  bent  down  at  C,  D,  pass  over  the  end 
of  the  die  at  the  left  where  the  shearing  punch  cuts  off  the  completed  piece 
of  work. 


CHAPTER  VI 
SHAVING  DIES  AND   THEIR  APPLICATIONS 

Shaving  dies  provide  a  means  of  finishing  blanked  or  pierced  parts  very 
accurately  and  with  a  perfectly  smooth  unbroken  edge.  In  spite  of  their 
serviceability  in  this  direction  they  are  used  only  to  a  limited  extent  in 
the  majority  of  shops  doing  press  work  and  in  many  they  are  practically 
unknown.  Yet  their  more  general  adoption  for  work  requiring  fairly  close 
limits  of  accuracy  would  result,  in  many  cases,  in  a  considerable  degree  of 
economy  in  the  long  run  and  the  product  throughout  would  be  turned  out 
to  greater  advantage,  so  far  as  concerns  correctness  of  outline  and  quality 
of  finish. 

Their  application,  however,  means,  in  most  instances,  the  running  of  the 
blanked  work  through  a  second  operation  and  this  naturally  has  much  to 
do  with  their  apparent  neglect  in  various  directions.  Still,  on  the  other 
hand,  where  accuracy  is  to  be  adhered  to  in  the  pressed  parts  and  smooth- 
ness of  contour  is  also  an  essential,  the  shaving  die  would  make  it  possible 
to  attain  the  desired  results  with  less  attention  to  the  quality  of  the  blank- 
ing dies  and  correspondingly  more  latitude  might  be  permissible  in  the  up- 
keep of  the  latter  tools. 

For,  where  the  piece  is  to  be  shaved  after  blanking  or  piercing,  the  exact 
size  to  which  the  work  is  produced  in  the  first  operation  need  not  be  given 
the  close  attention  that  would  otherwise  be  required,  for  a  slight  amount 
of  wear  in  the  dies  will  not  affect  the  completed  piece  as  the  shaving  tools 
will  bring  it  to  size.  And  this  means  that  in  the  making  of  the  blanking 
tools  originally,  a  little  more  leeway  is  permissible. 

USES  ON  HEAVY  STOCK 

As  heavier  gages  of  stock  come  to  be  considered,  the  shaving  die  be- 
comes almost  a  necessity  if  best  results  as  to  size  and  finish  are  to  be  ex- 
pected. For  the  heavy  stock  imposes  severe  duty  upon  the  blanking  dies 
with  corresponding  degree  of  wear,  and  the  thick  edge  of  the  blanked  metal 
is  apt  to  show  a  quality  of  roughness  that  is  oftentimes  unnoticed  with 
lighter  gage  material.  The  sharpness  of  the  corner  is  lost  and  the  edge 
may  assume  an  appearance  of  having  been  swaged  in  the  blanking  process. 
Also  the  cut  edge  may  be  rough  and  torn,  a  condition  likely  to  be  aggra- 
vated appreciably  with  certain  grades  of  stock  of  heavy  gage. 

121 


122  PUNCHES  AND  DIES 

Some  instances,  where  shaving  operations  are  of  prime  importance, 
are  as  follows:  Small  toothed  wheels  where  accurate  surfaces  are  required 
for  the  gear  tooth  curves  and  smooth  edges  are  essential.  Small  levers 
and  rocker  arms,  etc.,  where  certain  contact  points  or  bearing  surfaces 
must  be  exactly  finished  in  relation  to  other  portions  of  the  blank.  Toothed 
segments  and  sectors  where  the  conditions  are  similar  to  those  pertaining 
to  gear  wheels  as  noted  above.  Certain  pierced  members  requiring  exact 
relationship  between,  say,  a  cam  slot  or  a  central  opening  in  respect  to 
the  external  surface.  Here  an  internal  shaving  process  is  required  for 
the  pierced  openings  as  well  as  for  the  blanked  exterior. 

Occasionally  a  blanked  piece  has  to  be  shaved  only  at,  say,  one  end,  as 
for  a  rounded  bearing  point  or  a  short  contacting  projection.  In  such 
cases  the  shaving  dies  may  be  made  to  operate  only  on  the  limited  section 
where  special  qualities  of  accuracy  and  finish  are  desired.  In  such  in- 
stances the  shaving  tools  approach  in  function  certain  classes  of  trimming 
dies  where  the  action  of  the  tools  is  to  cut  away  a  small  amount  of  material 
at  some  point  on  the  edge  of  the  work  to  change  the  form  as  blanked  to  the 
modified  contour  desired,  as,  for  example,  in  trimming  a  rounded  lug  or 
shoulder  to  a  "  V"  or  other  form.  Usually,  however,  the  trimming  die  has 
a  considerable  amount  of  material  to  remove  and  is  thus  differentiated 
from  the  shaving  die  which,  as  its  name  implies,  takes  only  a  very  thin  cut, 
a  few  thousandths  at  the  most,  on  a  side.  In  fact  the  amount  left  for 
shaving  is  sometimes  divided  between  two  cuts  in  first  and  second  shaving 
dies  and  the  latter  is  then  required  to  remove  even  a  smaller  amount  of 
material  than  is  generally  left  for  the  single  shaving  operation. 

SHAVING  TOOLS  FOR  A  GEAR  WHEEL 

As  an  illustration  of  an  accurate  set  of  shaving  dies,  Fig.  165  is  pre- 
sented herewith  showing  the  application  of  the  double  shaving  principle, 
two  sets  of  shaving  dies  being  included  in  the  equipment  with  the  work  of 
shaving  divided  between  them ;  the  amount  left  for  the  second  shave  is  one- 
half  that  taken  off  by  the  first  shaving  dies.  While  there  are  as  stated  two 
shaving  operations  on  the  blank,  the  shaving  tools  are  essentially  the  same 
in  construction  as  a  single  shaving  set  would  be,  the  sole  difference  being 
in  respect  to  the  diameter  of  the  dies  which  in  the  present  instance  allow 
for  the  taking  of  the  two  cuts  which,  with  the  single  shaving  die  generally 
used,  would  be  confined  to  one  cut  only.  This  set  of  dies  has  been  selected 
as  the  first  illustration  in  the  present  chapter  for  the  reason  that  the  work 
produced  forms  a  characteristic  example  of  the  class  of  parts  to  which  the 
application  of  shaving  dies  is  especially  advantageous. 

The  blanking  tools  are  seen  to  the  left  in  the  half-tone  and  no  special 
description  is  required  as  they  are  of  practically  the  same  design  as  the  set 
of  wheel  dies  illustrated  by  Fig.  36  in  Chapter  II.  The  blank  produced  is 


SHAVING  DIES  AND  THEIR  APPLICATIONS  123 

a  ten-tooth  wheel  punched  out  of  0.050-in.  half  hard  steel  stock.  The 
outside  diameter  of  the  gear  wheel  is  0.751  in.,  the  depth  of  tooth  0.139  in. 
The  piece  is  used  on  a  calculating  machine  and  thirteen  wheels  are  re- 
quired for  each  machine. 


FIG.  165.  —  A  set  of  dies  for  blanking,  and  shaving  a  small  toothed  wheel 

THE  SHAVING  DIES 

The  two  sets  of  shaving  dies  are  alike  except  for  the  slight  difference  in 
diameter  of  punch,  die  opening,  and  nest.  The  sketch,  Fig.  166,  gives  the 
details  of  construction  with  a  few  important  dimensions.  The  die  proper 
is  of  tool  steel  finished  to  3  in.  diameter,  hardened,  and  finally  secured  by 
screws  and  dowels  to  the  shoe  or  base.  To  this  die  is  attached  the  nest, 
or  "set  edge,"  as  it  is  sometimes  called,  for  locating  the  work  over  the 
opening  in  the  die. 

As  the  shaving  die  is  used  expressly  for  securing  accuracy  in  the  work, 
as  well  as  smoothness  of  contour,  it  is  desirable  to  make  the  interior  of 
the  die  straight  instead  of  with  the  half  degree  clearance  on  a  side  com- 
monly found  in  blanking  dies.  At  the  same  time  the  difficulties  commonly 
encountered  in  working  out  such  a  die  opening  with  perfectly  straight 
sides  for  the  full  depth  of  one  inch  or  more  generally  results  in  the  adoption 
of  a  compromise  on  this  point  and  the  practice  in  various  shops  is  gener- 
ally to  work  the  die  out  straight  for  a  depth  of  fV  to  fVin.  dependent  upon 
the  thickness  and  nature  of  the  material  and  then  clear  the  die  below  the 
straight  portion. 

It  is  often  found  at  the  die  maker's  bench  that  the  attempt  to  produce 
a  perfectly  parallel  die  opening  from  top  to  bottom  results  in  a  bell-mouthed 
hole  instead  of  a  straight  one;  and  while,  in  various  instances  where  special 
requirements  demand  it,  straight  dies  can  be  and  are  regularly  produced, 


124 


PUNCHES  AND   DIES 


it  is  usually  considered  wiser  and  more  economical  practice  to  limit  the 
straight  portion  of  the  opening  to  the  amount  specified  above  and  clear 
the  remainder  of  the  depth  by  giving  each  side  the  customary  one-half 
degree  taper.  This  course  naturally  shortens  the  life  of  the  die  as  com- 
pared with  the  probable  working  period  through  which  it  might  be  used  if 


:   Clearance 


Dia.  of  Work  =  .751  'O.S. 
Thickness      =    .050'' 
Depth  of  Tooth  =.139" 


PLAN  OF  DIE 

FIG.  166.  —  Shaving  dies  for  small  gear 

made  with  no  side  clearance  at  all;  but,  with  the  usual  materials  finished 
by  shaving,  the  wear  on  the  dies  is  comparatively  slight  and  even  with 
their  limited  working  depth  (which  is  balanced  in  a  large  measure  by  the 
fact  that  only  a  small  amount  of  the  surface  is  removed  by  each  regrinding) 
they  should  answer  for  a  large  amount  of  work  before  requiring  replacement. 


SHAVING  DIES  AND  THEIR  APPLICATIONS  125 

With  shaving  dies  for  german  silver,  however,  it  is  customary  in  some 
shops  to  make  the  die  straight  or  parallel  all  the  way  through.  The 
shaving  of  such  material  imposes  severe  service  upon  the  cutting  edges  of 
the  tools  and  if  they  were  made  in  accordance  with  the  practice  noted  above 
their  life  would  be  very  materially  shortened. 

ALLOWANCES  FOR  SHAVING 

It  is  of  importance  at  this  point  to  give  a  little  consideration  to  the  sub- 
ject of  allowances  for  shaving  of  blanks.  As  for  any  given  material,  or 
grade  of  stock,  the  condition  of  the  contour  of  the  blank  will  vary  with  the 
thickness  of  the  metal,  the  amount  left  for  shaving  should  likewise  vary 
and  with  a  fair  degree  of  uniformity  from  the  thinner  gages  to  the  thick 
material.  Similarly  the  allowance  for  any  given  thickness  should  vary  for 
soft,  half-hard,  and  hard  material.  In  order  to  cover  these  allowances  for 
steel  blanks  of  the  three  grades  noted,  Table  12  has  been  developed  and 
has  been  given  thorough  tests  in  connection  with  numerous  shaving  dies 
operating  on  different  classes  of  work. 

This  table  covers  thicknesses  of  metal  from  -fa  in.  to  i  in.  inclusive 
and  also  includes  allowances  for  german  silver  and  brass.  For  the  latter 
two  materials,  it  will  be  noted,  the  shaving  allowances  are  double  those  for 
steel  of  the  same  thickness.  Table  13  is  arranged  to  give  allowances  where 
two  shaving  cuts  are  taken.  From  the  quantities  under  the  heading 
"  Allowances  for  second  shave"  it  will  be  seen  that  the  amount  left  for  the 
second  shaving  operation  is  one-half  that  for  the  first.  Thus  in  the  case 
of  a  soft  steel  blank  TVin-  thick  requiring  two  shaving  cuts,  0.003  in. 
would  be  allowed  on  a  side  for  the  first  shaving  die  to  remove  and  0.0015 
in.  for  the  second  shaving  operation,  or  a  total  of  0.0045  in.  on  a  side  or 
0.009  in.  over  all,  the  blanking  dies  being  made  0.009  in.  larger  than  the 
finished  size  of  the  piece. 

Referring  back  to  the  dies  in  Figs.  165  and  166,  for  the  gear  wheel  of 
0.050  in  half  hard  steel,  the  first  shaving  die  would  be  made  to  remove  0.003 
in.  on  a  side  and  the  second  shaving  die  to  finish  the  piece  by  removing 
0.0015  in.  from  each  side.  The  blanking  tools  then  must  be  made  larger  in 
diameter  than  the  finish  gear  dimensions  by  twice  the  sum  of  these  two 
allowances  or  0.009  in. 

NESTS  FOR  THE  WORK 

« 

The  form  of  nest  or  locating  device  on  shaving  dies  varies  with  the  form 
and  size  of  the  work  but  there  are  certain  conditions  to  be  observed  in 
common  in  practically  all  cases.  Thus  as  much  clearance  as  feasible  should 
be  provided  at  the  under  side  of  the  nest  to  allow  for  the  ready  blowing  out 
of  all  chips  produced  in  the  shaving  process;  the  top  face  of  the  nest  should 
be  beveled  out  or  chamfered  around  the  contour  of  the  opening  to  provide 


126 


PUNCHES  AND  DIES 


an  easy  locating  medium  for  the  work;  the  nest  opening  itself  should  be 
just  enough  larger  than  the  blanked  piece  to  admit  the  latter  readily  but 
without  permitting  it  side  "play.  It  should  ordinarily  be  the  size  of  the 
blanking  punch  and  it  may  therefore  be  finished  by  using  the  blanking 
punch  for  a  final  broaching  tool  in  working  the  nest  opening  to  diameter. 
Under  this  condition  ample  clearance  will  be  formed  in  the  nest  opening 
for  the  shaving  punch  as  the  latter  is  a  close  fit  to  the  shaving  die  and  is 
therefore  at  least  several  thousandths  under  the  diameter  of  the  nest  itself. 
As  to  the  chip  clearance  at  the  underside  of  the  nest  this  may  well  be 
equal  to  about  two-thirds  the  thickness  of  the  blanks.  A  good  standard 
for  the  nest  thickness  for  the  general  run  of  shaving  dies  is  J  in.  as  indi- 
cated in  the  sketch  in  Fig.  166  and  with  the  above  ratio  of  clearance  space 
underside  the  gap  cut  out  for  a  blank  0.050-in.  thick  will  be  0.033  in.  as 
given  on  the  detail. 


V't 


± 


FIG.  167.  —  Progressive  piercing  and  blanking  tools  and  a  pair  of  shaving  dies 

The  shape  of  the  outside  of  the  nest  is  best  developed  toward  an  approxi- 
mation of  the  contour  of  the  blank  to  facilitate  the  maintenance  of  a  per- 
fectly clean  surface  under  the  nest  itself  and  across  the  face  of  the  die. 
This  applies  more  particularly  where  the  shaving. die  is  of  the  pattern 
illustrated  in  Fig.  166  with  opening  clear  down  to  allow  the  work  as  shaved 
to  pass  down  through  the  die  and  shoe. 

OTHER  DESIGNS  OF  SHAVING  TOOLS  . 

While  the  foregoing  method  of  shaving  blanks  by  pressing  them  down 
through  the  die  one  after  another,  is  presumably  the  most  commonly  em- 
ployed, there  are  numerous  instances  where  such  dies  are  designed  for 
ejecting  the  shaved  blank  from  the  top  of  the  die.  Also,  the  tools  are 
occasionally  arranged  to  operate  in  inverted  order  with  the  die  at  the  top 
and  the  punch  below.  Then  again,  while  the  conventional  nest  is  one  that 


SHAVING  DIES  AND  THEIR  APPLICATIONS 


127 


IReq.  „ 

,125  "x  15/8"X.19/B 
H.S.  Steel 


V 


FIG.' 16  8 

A  Blank  Requiring  Chains 


locates  the  blank  on  the  die  by  means  of  its  external  edge  or  contour, 
examples  are  frequently  found  where  an  opening  at  the  center  or  in  some 
other  portion  of  the  blank  allows  an  internal  nest  or  pilot  to  be  employed 
to  advantage,  particularly  where  it  is  desired  to  shave  the  edge  in  accurate 
relationship  to  a  pierced  hole  of  this  char- 
acter. An  illustration  of  this  arrangement 
is  presented  in  Fig.  167. 

A  PILOTED  SHAVING  DIE 

Referring  to  this  view,  a  set  of  progres- 
sive piercing  and  blanking  tools  will  be 
seen  to  the  left,  while  at  the  right-hand 
side  is  shown  the  shaving  punch  and  die. 
The  blank  produced  with  the  progressive 
dies  is  sketched  in  Fig.  168  and  will  be 
seen  to  be  a  steel  disk  IJ-in.  diameter  by 
f-in.  thick,  with  six  90-degree  notches  in 
the  edge  and  a  central  hole  measuring 
0.4937-in.  diameter.  One-half  inch  from 
the  center  there  is  a  J-in.  hole  which  is 
pierced  at  the  same  time  as  the  central 
opening. 

For  the  shaving  operation  that  follows, 
a  die  is  used  which  is  fitted  with  a  spring 
knock-out  or  ejector  in  the  top  of  which  a 
TVin.  locating  pilot  or  nest  pin  is  secured 
while  a  f-in.  pin  is  placed  at  a  distance 
of  \  in.  to  correspond  with  the  smaller  of 
the  pierced  holes  in  the  blank.  The  two 
pilots  thus  serve  as  a  means  for  locating 
the  blanks  for  the  shaving  process. 

The  construction  of  the  die  is  brought  out  by  the  sectional  view,  Fig. 
169,  which  is  included  here  to  represent  the  method  of  removing  the  shaved 
piece  from  the  die  opening.  The  knock-out  A  is  f-in.  thick  and  has  a 
possible  movement  down  into  the  die  opening  of  f  in.  It  is  provided 
with  a  series  of  pins  B  which  are  acted  upon  by  the  heavy  pressure  spring 
C  to  lift  the  knock-out  and  eject  the  shaved  blank.  The  spring  is  confined 
between  two  disks  and  the  central  stud  tapped  into  the  bottom  of  the  die 
shoe  secures  the  attachment  in  place.  It  may  be  readily  transferred  to 
any  other  die  requiring  similar  knock-out  apparatus. 

As  stated  the  knock-out  disk  A  carries  the  central  locating  pilot  for 
receiving  the  work  and  also  has  a  second  pin  for  entering  the  f-in.  hole 
in  the  blank.  The  punch  is  provided  with  a  central  hole  for  the  top  of  the 


^  C   CROSS 
^'SECTION 


FIGS. 


F.ic.169 

168-169.  —  Sectional  view  of 
shaving  dies 


128 


PUNCHES  AND  DIES 


pilot  pin.  The  disk  finished  with  these  tools  is  part  of  the  mechanism  of  a 
coin  register.  Another  piece  for  the  same  machine  is  shaved  with  the  tools 
illustrated  in  Fig.  170. 

INVERTED  SHAVING  DIES 

These  tools  are  of  the  inverted  type  and  the  blank  is  located  by  placing 
it  over  a  nicely  fitted  pilot  which,  in  this  construction,  is  inserted  in  the 
punch,  the  latter  forming  the  lower  member  of  the  set  of  tools.  The 
shaving  tools  are  at  the  left  in  Fig.  170  while  at  the  right  in  the  same  view 
are  a  set  of  progressive  blanking  and  piercing  dies  for  piercing  the  central 
hole  and  producing  the  blank  ready  for  shaving.  The  piece  itself  is  shown 
with  principal  dimensions  in  Fig.  171. 

It  is  a  gear  wheel  of  steel,  J-in.  thick,  1.875  in.  outside  diameter,  with 
28  teeth  which  must  be  accurately  finished  on  their  contours  and  concenr 


FIG.  170.  —  Dies  for  making  a  gear  wheel 

trie  with  the  0.406  in  hole  at  the  center.  The  shaving  die,  which  is  adapted 
to  be  attached  to  the  ram  of  the  press  instead  of  to  the  bolster,  and  thus 
used  bottom  side  up,  as  shown  by  Fig.  172,  is  made  up  in  the  same  manner 
as  if  constituting  the  usual  lower  member  of  the  set.  It  is  finished  inter- 
nally to  the  size  for  shaving  for  a  depth  of  f  in.  and  is  cleared  beyond  that 
point. 

In  use,  the  work  is  located  on  the  punch  face  by  means  of  the  pilot  and 
the  die  upon  descending  with  the  press  slide  accomplishes  the  shaving 
operation  and  rises  with  the  blank  inside.  The  clamp  on  the  front  of  the 
slide  for  holding  punch  shanks  is  removed  from  the  slide  to  leave  a  liberal 
opening  over  the  top  of  the  die  shoe  and  as  the  shaved  blanks  pass  one  by 
one  up  through  the  die  they  are  swept  out  of  the  slide  opening  by  the 
operator.  With  both  of  the  shaving  dies  in  Figs.  167  and  170,  the  seat  for 
the  blank  is  readily  kept  free  of  chips  and  dirt  and  there  is  no  trouble  in 
nesting  the  work  properly. 


SHAVING   DIES  AND  THEIR  APPLICATIONS 


129 


.125  x  2  x.  115/iG  H.H.  Steel 


16  P-28-T 

FIG.  171 


Press  Slide 


COMPARATIVE  ADVANTAGES 

The  two  types  of  dies,  as  best  seen  in  the  sectional  views,  Figs.  169  and 
172,  have  their  advantages  for  certain  classes  of  blanks  requiring  shaving, 
not  the  least  of  which  is  the  feature  just  referred  to,  the  convenience  with 
which  the  die  face  is  kept  clean.  The  dies  in  Fig.  169  are  used  in  this  par- 
ticular instance  for  a  thick 

1     "D«~ 

blank;  with  thinner  work 
the  advantages  of  the 
knock-out  are  more  ap- 
parent, for  the  disk  A  then 
serves  as  a  holder  to  con- 
fine the  blank  between  its 
face  and  the  end  of  the 
punch  and  by  supporting 
the  work  fully  during  the 
shaving  operation  it  as- 
sures its  being  ejected  from 
the  die  in  a  perfectly  flat 
condition. 

The  knock  -  out  also 
prevents  possibility  of 
thin  shaved  blanks  stack- 
ing up  or  wedging  tightly 
in  the  die  with  likelihood 
of  injury  to  themselves 
and  the  tools.  This  pos- 
sible source  of  trouble  with 
such  work  is  guarded 
against  in  a  measure  in 
the  usual  type  of  die  with 
opening  clear  through,  by 
confining  the  sizing  part 
of  the  die  to  a  limited 
depth  of  T3g-  to  fV  in.  as 
already  pointed  out  in  this 
chapter.  The  clearance  below  then  allows  the  work  to  pass  out  freely 
at  the  bottom.  This  occasional  tendency  upon  the  'part  of  shaved 
blanks  to  stack  up  in  the  die  is  quite  similar  to  the  action  of  slugs  from 
a  piercing  punch  which  with  an  improperly  cleared  die  will  tend  to  swage 
against  each  other  and  the  sides  of  the  die  opening  and  cause  trouble  of  a 
more  or  less  serious  nature. 

With  the  inverted  type  of  die  in  Fig.  172  the  chips  or  shavings  re- 


Opening  in  Slide 

for  Punch  Clamp, 

Shaved  Work  Passes 

up  into  Opening  here 


!•*— 17875-^1 
Guide  Pillars      p| 


id 


FIG.  172 

FIGS.  171-172.  —  Method  of  resting  the  work  on  a 
pilot  with  inverted  die 


130 


PUNCHES  AND  DIES 


moved  from  the  edge  of  the  blank  at  each  down  stroke  of  the  press 
are  carried  down  over  the  edge  of  the  punch  from  which  they  are  readily 
cleared. 

TOOLS  FOR  A  TOOTHED  CAM  MEMBER 

The  shaving  of  an  unusual  form  of  blank,  requiring  the  accurate  finish- 
ing of  two  or  three  different  surfaces,  external  and  internal,  involves  at 


FIG.  173.  —  Blanking  die  and  a  shaving  die  for  outside  of  work 


FIG.  174.  —  Dies  for  piercing  and  shaving  center  hole  and  notched  teeth 

times  the  application  of  several  distinctive  shaving  operations  in  as  many 
separate  dies.  It  is  a  problem  of  this  character  that  is  taken  care  of  by 
means  of  the  tools  in  the  views  that  immediately  follow : 

The  three  photographs,  Figs.  173, 174,  and  175,  represent  three  sets  of 
tools,  each  made  up  of  two  pairs  of  dies  for  blanking,  piercing,  and  shaving 
the  piece  shown  by  Fig.  176  which  is  one  of  nine  similar  members  used  in  a 


SHAVING  DIES  AND  THEIR  APPLICATIONS 


131 


FIG.  175.  —  Dies  for  piercing  and  shaving  a  cam  slot 


Vls    Rad.     20  Sides 
10  Grooves    .125  Deep 
37  Divisions  to  Circle 


.077  Deep    Spaced 
37  Divisions  to  Circle 


Cam  Slot  .095 


Radius  "A"  =1.2875 
»  "B"  =1.1625 
••  "c"  =1.0675 

"D"=  .9725  x  8  Divisions  -.015 

"E"=  .9825 

"F"  =  .8875  x  8  Divisions  +.015 

"G"=  .7875 


FIG.  176.  —  The  work  produced  in  the  tools  in  Figs.  173-174-175 


132  PUNCHES  AND  DIES 

calculating  machine  and  constituting  as  a  group  what  is  known  as  a  setting 
drum. 

The  nine  drum  disks  are  all  made  to  the  dimensions  given  for  outer 
diameter,  diameter  of  center  hole,  size  of  teeth  inside  and  out,  and  length 
and  width  of  the  cam  slot.  The  angular  relation,  however,  of  the  latter 
slot  in  respect  to  the  groups  of  teeth  and  the  projecting  lug  at  one  side, 
varies  throughout  the  set  of  disks;  for  the  cam  slot  in  each  is  utilized  to 
operate  an  individual  controlling  key  which  is  adjusted  radially  through 
the  necessary  distance  by  the  cam  slot  which  acts  upon  the  head  of  the  key. 
The  position  of  the  rise  in  the  cam  slot  is  therefore  of  importance  and  its 
variation  around  the  disk  as  a  whole  throughout  the  series  of  nine  disks  has 
led  to  the  design  of  a  group  of  press  tools  of  unusual  interest. 

GENERAL  PRINCIPLES 

The  disks  are  of  german  silver  0.050-in.  thick  and  they  are  blanked 
from  stock  2f  in.  wide.  The  blanks  for  the  series  are  all  alike  externally 
and  so  one  set  of  blanking  tools  answers  for  all  of  them. 

This  blanking  operation  is  followed  by  an  external  shaving  cut  which 
finishes  the  outside  contour  completely.  Then  the  shaved  blanks  are 
passed  through  a  set  of  piercing  dies  which  form  the  hole  at  the  center  and 
the  internal  teeth.  This  operation  is  followed  by  the  shaving  of  the  center 
opening  and  the  inner  teeth,  and  then  the  cam  slot  is  pierced  and  in  another 
set  of  dies  the  slot  is  shaved. 

Up  to  the  point  where  the  slot  is  to  be  pierced  the  disks  are  all  uniform, 
involving  no  complications  in  the  construction  of  the  dies.  But,  for  the 
operations  in  connection  with  the  slots,  special  forms  of  nesting  devices  are 
required  in  order  to  give  each  slot  the  exact  individual  position  necessary 
for  that  particular  number  of  disk.  That  is,  there  are  nine  distinct  posi- 
tions for  the  slots  in  the  different  disks  and  this  variation  is  secured  by  an 
adjustable  nest  which  enables  one  set  of  dies  to  pierce  all  slots  correctly 
and  another  set  to  shave  them  accurately,  thus  avoiding  the  necessity  of 
nine  separate  sets  of  dies  each  for  piercing  and  shaving. 

BLANKING  AND  CENTER  PIERCING 

The  blanking  dies  for  the  disk  are  shown  to  the  right  in  Fig.  173  and 
require  no  special  description  as  they  are  similar  in  general  design  to 
various  other  tools  already  shown  in  detail  in  other  chapters  in  this  book. 
It  will  be  noticed  that  the  trigger  form  of  stop  is  used  for  the  stock  and  the 
dies  are  so  laid  out  as  to  bring  the  projecting  lug  of  the  blank  at  an  angle 
of  about  30  degrees  with  the  cross  center  line  to  permit  of  the  use  of  a 
minimum  width  of  stock.  The  punch  resembles  one  for  an  interrupted 
tooth  wheel  and  the  portion  for  blanking  out  the  lug  is  dovetailed  into  the 
edge  of  the  body  of  the  punch.  Three  fillister  head  screws  and  three 


SHAVING  DIES  AND   THEIR  APPLICATIONS 


133 


dowels  locate  and  secure  the  punch  to  its  holder  or  head,  which,  as  will  be 
seen,  forms  with  the  die  base  a  set  of  subpressed  or  pillar  dies. 

The  shaving  tools  at  the  left  in  Fig.  173  are  provided  with  a  locating 
nest  shaped  along  similar  lines  to  the  one  described  in  connection  with 
Fig.  166,  although  the  proportions  are  somewhat  different  to  correspond 
with  the  larger  size  of  the  blank  to  be  shaved.  The  stock  being  0.050  in. 
thick,  the  amount  removed  on  a  side  by  the  shaving  die  is  0.005  in.  as 
indicated  by  the  value  for  that  thick- 
ness under  the  column  for  german 
silver  in  Table  12. 

The  dies  at  the  right  in  Fig.  174 
pierce  the  center  opening  and  form 
the  internal  teeth  and  the  tools  at 
the  left  in  the  same  view  accomplish 
the  internal  shaving  operation  re- 
quired for  finishing  the  inside  con- 
tour. The  nesting  of  the  blank  is 
accomplished  in  the  same  manner 
for  both  sets  of  dies  and  the  sketch, 
Fig.  177,  will  give  a  good  idea  of  the 
general  arrangement  of  the  various 
parts  of  the  tools.  While  the  latter 
view  is  more  specifically  related  to 
the  shaving  dies  it  represents  as  well 
the  essential  features  of  the  dies  for 
the  piercing  operation. 

The  form  of  the  nest  is  a  close 
outline  of  the  blank  and  its  depth  of 
J  in.  is  relieved  around  the  opening 
by  a  liberal  chamfer  which  removes 
the  corner  for  one-half  the  thickness 
of  the  nest.  The  punch  is  provided 
with  a  combined  pressure  plate  and 
stripper  which  serves  to  hold  the 
work  flat  during  the  operation  of  the 


FIG. 


177.  —  Arrangement  of 
shaving  die 


[nest"  on 


punch  and  which  strips  the  punch  upon  the  upstroke  of  the  slide.  Both 
dies  for  the  piercing  and  shaving  cuts  are  provided  with  ejectors  in  the 
form  of  vertical  pins  A  which  are  located  under  the  blank  and  which  are 
operated  by  downward  pressure  upon  the  end  of  the  handle  B. 

PIERCING  AND  SHAVING  THE  CAM  SLOT  • 

Proceeding  now  to  Fig.  175,  we  find  here  some  most  interesting  features 
in  die  construction.     These  tools  pierce  and  shave  the  cam-shaped  opening 


134 


PUNCHES  AND   DIES 


PLAN  OF  DIE 

FIG.  178.  —  Details  of  slot  shaving  die 


SHAVING  DIES  AND  THEIR  APPLICATIONS 


135 


and  as  they  are  alike  in  the  main  the  description  may  well  be  confined  to 
the  shaving  die  details  which  are  clearly  brought  out  by  the  drawing,  Fig. 
178,  and  by  the  photographic  groups,  Figs.  179  and  180,  which  show  the 
principal  die  parts  as  they  appear  when  the  tools  are  taken  apart. 


FIG.  179,  —  Slot  shaving  dies  taken  apart 


FIG.  180.  —  Details  of  slot  shaving  dies 

These  dies,  as  pointed  out,  cover  in  the  one  set  the  positioning  of  the 
nine  differently  located  slots  in  the  disks.  They  are  of  sectional  construc- 
tion with  punch  and  die  proper  each  made  up  of  two  parts  ground  to  cor- 
rect relationship  to  one  another. 

Referring  now  to  Figs.  178, 179,  and  180,  where  the  same  reference  letters 
are  used  for  the  three  engravings,  A  is  the  main  portion  of  the  die  which  is 
pressed  into  a  steel  ring  B  by  which  it  is  secured  to  the  die  shoe.  This  die 


136  PUNCHES  AND  DIES 

A  is  finished  out  to  a  radius  of  0.9825  in.  except  for  the  portion  for  the 
high  part  of  the  cam  slot  which  is  cut  out  to  a  radius  of  1.0675  in.  The 
greater  part  of  the  bore  may  therefore  be  finished  by  grinding  to  a  diameter 
equal  to  twice  radius  0.9875  or  1.9750  in. 

The  smaller  section  of  the  die  proper  shown  at  C  is  ground  for  the 
greater  part  of  its  circumference  to  a  diameter  corresponding  to  the  interior 
of  the  main  die  A  and  made  to  fit  closely  therein.  A  part  of  the  circum- 
ference of  C  is,  however,  reduced  to  a  radius  of  0.8875  in.  for  the  low  portion 
of  the  cam  slot,  this  being  shown  at  x;  and  at  y  another  portion  of  the  out- 
side surface  is  reduced  to  a  radius  of  0.9725  in.  to  give  the  proper  width  of 
gap  between  that  portion  and  the  corresponding  edge  yr  of  the  main  die  A . 
These  figures  may  be  checked  up  with  the  radii  given  on  the  drawing  of  the 
work  in  Fig.  176  and  will  give  a  clear  idea  of  the  manner  in  which  the  proper 
width  of  slot  is  provided  for  between  the  opposing  faces  of  the  two  die 
members  described.  The  position  of  the  holes  for  the  screws  and  dowel 
pins  for  securing  the  die  parts  to  the  base  or  shoe  will  be  seen*  in  the  draw- 
ing, Fig.  178,  and  also  in  the  group  photographs. 

THE  PUNCH  PARTS 

Similarly,  the  punch  proper  is  constructed  with  two  parts,  outer  and 
inner,  which  facilitate  the  making  of  these  members.  The  larger  punch 
part  D  is  made  with  a  piercing  projection  of  long  enough  arc  to  cover  the 
high  portion  of  the  cam  slot  while  the  inner  member  E  is  constructed  to 
pierce  the  low  portion  of  the  slot. 

The  base  of  the  punch  E  is  finished  to  fit  closely  in  the  opening  through 
the  bottom  of  punch  D  and  the  two  members  when  put  together  over-lap 
at  the  cutting  ends  as  at  z  to  give  a  smooth  continuous  cut  through  the  slot 
at  the  point  where  high  and  low  cam  slots  meet  and  the  edges  of  both  punch 
parts  are  beveled  at  the  necessary  angle  at  z  to  give  the  correct  slope  to  the 
cam  slot  rise.  The  cutting  portions  of  both  punch  members  are  ground 
after  hardening  to  give  the  required  inside  and  outside  radii. 

THE  ADJUSTABLE  NEST 

The  work  to  be  shaved  is  placed  in  the  adjustable  nest  F,  where  it  fits 
with  its  shaved  center  located  over  the  thin  pilot  disk  G,  and  with  its  pro- 
jecting lug  in  the  notch  in  the  nest  at  H.  The  latter  gives  all  the  pieces 
to  be  shaved  a  definite  position  in  the  nest  and  it  remains  only  to  adjust  the 
nest  upon  the  die  to  secure  any  desired  location  around  the  circle  for  the 
cam  slots.  This  adjustment  is  secured  as  follows:  The  nest  is  seated  by  a 
recess  in  its  underside  which  fits  over  the  top  of  the  die  ring  A.  It  is 
adapted  to  be  clamped  in  position  by  the  four  screws  passed  through  the 
curved  slots  near  the  edge.  At  the  front  is  secured  a  short  arm  I  which  is 
engaged  by  the  opposing  thumb  screws  J  for  adjustment  either  to  right  or 


SHAVING  DIES  AND  THEIR  APPLICATIONS 


137 


left.  Thus  while  the  punch  and  die  remain  in  fixed  position,  the  nest  and 
work  may  be  set  around  to  a  master  for  the  locating  of  the  slot  according  to 
the  requirements  for  that  particular  job.  After  one  lot  have  been  run 
through  the  dies,  the  nest  is  reset  for  the  next  number  in  the  series  of  cam 
disks  and  so  on  with  the  entire  lot. 

The  punch  holder  is  fitted  with  a  spring  actuated  pressure  pad  and 
stripper  K  which  is  backed  by  five  springs,  one  of  which  is  located  at  the 
center  where  it  passes  up  through  the  sectional  punch  into  contact  with  the 
back  of  the  stripper.  There  is  a  knock-out  in  the  die  slot,  actuated  by  the 
handle  M,  for  ejecting  chips  and  a  pin  knock-out  at  N  operated  by  handle 
0  for  lifting  the  finished  work  from  the  die. 

Between  the  piercing  tools  and  the  shaving  dies  made  to  the  same 
general  design  as  the  ones  just  described,  there  exists  but  few  points  of 


FIG.  181.  —  Shaving  dies  with  open  nest 

difference.  The  piercing  dies  are  enough  smaller  than  the  shaving  tools 
to  allow  the  right  amount  of  material  for  a  satisfactory  shaving  cut  which 
has  been  determined  to  be,  for  this  thickness  of  work,  0.005  in.  on  each 
side. 

SPECIAL  FORM  OF  NEST  FOR  A  THICK  BLANK 

In  shaving  blanks  of  unusual  thickness  the  chip  removed  is  likely  to 
prove  troublesome  if  the  work  is  located  in  the  customary  form  of  nest,  for 
it  is  usually  impossible  to  provide  sufficient  clearance  under  the  latter  to 
take  care  of  the  relatively  thick,  deep  shavmg  removed  from  the  contour 
of  the  blank.  In  such  instances  an  open  nest  may  be  employed  along  the 
lines  of  the  one  used  on  the  die  in  Figs.  181  and  182. 


138 


PUNCHES  AND  DIES 


The  shaving  tools  here  represented  operate  on  a  half  hard  steel  blank 
eVinch  thick  although  the  piece  itself  is  only  IfV  in.  long  over  all.  The 
amount  shaved  from  each  side  is  about  0.010  in.  and  an  enveloping  nest 
would  consequently  be  impracticable  for  the  reason  noted  above.  So  the 


FIG.  182.  —  Construction  of  dies  with  special  form  of  nest 

nest  was  constructed  as  shown,  with  a  fixed  V  for  locating  one  end  and  a 
swinging  latch  at  the  opposite  end  which  is  actuated  by  a  spring  to  force 
the  blank  into  central  position  over  the  die  opening. 

The  two  nest  elements  are  shown  at  A  and  B,  Fig.  182,  the  former  with 
its  narrow  V  notch  for  receiving  the  round  end  of  the  blank,  the  latter  with 
a  wider  V  for  centering  the  broad  end  of  the  work.  The  spring  for  con- 
trolling the  swinging  member  B  is  compressed  between  the  heel  at  the  rear 


SHAVING  DIES  AND  THEIR  APPLICATIONS 


139 


of  the  pivot  and  a  drilled  post  C  secured  at  the  back  of  the  die  base.  Both 
parts  A  and  B  are  cut  away  underside  for  chip  clearance,  as  indicated  by 
the  dotted  lines  in  the  plan  view  in  Fig.  182.  The  edge  formed  by  this  clear- 
ance cut  acts  as  a  stripper  for  the  punch.  The  swinging  arm  or  gate  B 
allows  the  operator  to  keep  the  face  of  the  die  free  from  chips  and  to  place 
successive  blanks  in  position  with  ease  and  rapidity. 

OTHER  FORMS  OF  DIES 

It  will  be  noticed  that  all  of  the  examples  of  shaving  dies  illustrated  in 
this  chapter  are  provided  with  guide  pins  or  pillars  to  assure  correct  aline- 
ment  of  punch  and  die,  which  is  an  essential  feature  with  such  tools.  This 
form  of  construction  is  in  fact  coming  into  general  use  in  progressive  shops 
for  a  large  share  of  the  press  work  handled  in  other  classes  of  dies  as  well 
as  in  shaving  tools. 

The  shaving  dies  in  the  preceding  pages  have  all  been  shown  as  used 
for  direct  finishing  of  parts  produced  in  some  form  of  blanking  die.  There 
are,  however,  in  different  press  rooms  numerous  cases  where  shaving  tools 
are  employed  for  operations  on  blanks  that  are  passed  through  trimming 
dies  before  shaving,  or  produced  at  the  outset  in  trimming  dies  without 
preliminary  blanking.  .  Then,  again,  there  are  various  interesting  examples 
of  shaving  dies  combined  in  one  set  with  trimming  tools  so  that  the  two 
distinct  operations  are  performed  in  progressive  fashion. 

In  the  chapter  that  follows  a  number  of  trimming  dies  are  illustrated 
and  in  conjunction  with  them  several  further  types  of  shaving  tools  are 

shown. 

% 

TABLE  12.  —  AMOUNT  TO  ALLOW  ON  A  SIDE  FOB  SHAVING  CONTOUR  WHERE  ONLY  ONE 

SHAVE  is  TAKEN 


Thickness  of 
blank 

Soft  steel 

Half-hard 
steel 

Hard  steel 

German 
silver 

Brass 

Thickness  of 
blank 

Inch 

Inch 

Inch 

Inch 

Inch 

Inch 

[Inch 

£  (0.0468) 

0.0025 

0.003 

0.004 

0.005 

0.005 

A  (0.0468) 

A  (0.0625) 

0.003 

0.004 

0.005 

0.006 

0.006 

&  (0.0625) 

•h  (0.078) 

0.0035 

0.005 

0.006-0.007 

0.007 

0.007 

A  (0-078) 

&  (0.0938) 

0.004 

0.006 

0.007-0.008 

0.008' 

0.008 

A  (0.0938) 

<k  (0.1094) 

0.005 

0.007 

0.009-0.011 

0.010 

0.010 

A  (0.1094) 

1  (0.125) 

0.007 

0.009 

0.012-0.014 

0.014 

0.014 

t  (0.125) 

140 


PUNCHES  AND   DIES 


TABLE  13.  —  AMOUNT  TO  ALLOW  ON  A  SID®  FOR  SHAVING  CONTOUR  WHERE  A  SECOND 
SHAVING  OPERATION  is  USED 


Allowance  for  first  shave 

Allowance  for  second  shave 

Thickness  of 
blank 

Half 

Half 

Thickness  of 
blank 

Soft 

hard 

Hard  steel 

hard 

Hard  steel 

steel 

steel 

Inch 

Inch 

Inch 

Inch 

Inch 

Inch 

Inch 

Inch 

A  (0.0468) 

0.0025 

0.003 

0.004 

0.00125 

0.0015 

0.002 

&  (0.0468) 

&  (0.0625) 

0.003 

0.004 

0.005 

0.0015 

0.002 

0.0025 

A  (0-0625) 

-h  (0-078) 

0.0035 

0.005 

0.006-0.007 

0.00175 

0.0025 

0.003  -0.0035 

A  (0-78) 

•h  (0.0938) 

0.004 

0.006 

0.007-0.008 

0.002 

0.003 

0.0035-0.004 

A  (0.0938) 

A  (0.1094) 

0.005 

0.007 

0.009-0.011 

0.0025 

0.0035 

0.0045-0.0055 

A  (0  1094) 

i  (0.125) 

0.007 

0.009 

0.012-0.014 

0.0035 

0.0045 

0.006  -0.007 

t  (0.125) 

CHAPTER  VII 
TRIMMING  DIES  — TRIMMING  AND   SHAVING 

There  are  two  general  classes  of  trimming  dies.  One  class  includes  those 
which  are  used  for  removing  the  burr  and  superfluous  metal  from  such 
articles  as  drawn  shells,  utensils  of  one  kind  or  another,  and  other  cylindrical 
and  square  containers,  boxes  and  the  like  where  extra  metal  which  must  be 
allowed  in  the  blank  for  the  processes  of  drawing  and  forming  has  to  be 
removed  in  the  form  of  a  rim  during  or  following  the  drawing  or  forming 
operations,  according  to  whether  the  work  is  performed  with  simple,  pro- 
gressive, or  combination  dies. 

The  other  class  of  trimming  dies  is  employed  for  operating  upon  the 
contour  of  a  blank  or  upon  some  portion  of  an  article  of  either  regular  or 
irregular  form  which  may  require  the  cutting  out  of  a  notch  or  other  open- 
ing along  the  edge,  or  the  finishing  of  one  or  more  sides  or  edges  by  cutting 
out  some  part  of  the  metal  at  the  necessary  points. 

The  first  class  of  trimming  dies  referred  to  above  is  the  more  commonly 
used  but  as  they  are  closely  identified  with  the  operations  of  drawing  and 
forming  which  have  not  as  yet  been  described  in  detail  in  this  book,  they 
will  be  considered  later.  The  present  chapter  will  be  confined  to  trim- 
ming dies  of  the  character  noted  in  the  preceding  paragraph. 

GENERAL  ADVANTAGES 

These  trimming  dies,  while  of  wide  importance  in  the  press  shop,  are  not 
employed  to  anything  like  the  degree  that  they  should  be,  and  in  this  re- 
spect their  status  is  something  like  that  of  the  shaving  tools  to  which  a 
chapter  has  already  been  devoted.  Oftentimes  their  work  is  quite  similar 
to  the  operations  performed  with  shaving  dies  although  as  a  rule  they 
differ  from  the  latter  in  that  they  usually  modify  the  shape  of  the  work 
materially,  or  if  made  to  follow  closely  some  portion  of  the  contour  they  are 
generally  designed  to  remove  a  much  greater  amount  of  metal  than  is  the 
practice  with  shaving  dies,  which,  as  already  explained,  are  intended  for 
taking  a  cut  of  a  few  thousandths  of  an  inch  only,  at  the  most.  Occasion- 
ally, shaving  dies  are  used  to  finish  some  part  of  an  object  already  brought 
closely  to  size  by  trimming;  and  the  operations  of  trimming  and  shaving 
are  sometimes  combined  in  progressive  types  of  tools  for  making  a  piece 
complete  from  a  strip  of  stock,  which  is  first  operated  upon  by  the  trimming 

141 


142 


PUNCHES  AND  DIES 


dies  to  give  the  required  outline  at  the  edge,  then  advanced  to  the  second 
position  in  the  press  where  the  shaving  tools  finish  the  trimmed  portion, 
then  advanced  again  for  cutting  off  with  a  parting  tool,  after  which  each 
stroke  of  the  press  slide  results  in  the  production  of  a  finished  blank. 

Trimming  dies  facilitate  the  production  of  many  articles  that  it  would 
be  practically  impossible  to  make  in  blanking  tools  alone  or,  if  actually 
admitting  of  such  treatment,  would  necessitate  the  employment  of  un- 
necessarily expensive  and  complex  dies  whose  first  cost  and  later  upkeep 
would  amount  to  an  undesirable  total.  Again,  where  several  different 
parts  are  to  be  manufactured  to  the  same  form,  but  of  varying  width  or 
length,  involving  ordinarily  a  set  of  blanking  dies  for  each  length  of  piece, 
the  adoption  of  a  trimming  die  makes  it  possible  to  blank  all  of  the  pieces 


FIG.  183.  —  Trimming  tools 

uniformly  in  a  single  set  of  dies  and  then  trim  them  to  their  individual 
lengths,  thus  eliminating  the  necessity  for  more  than  the  one  set  of  first 
operation  tools. 

SIMPLE  TRIMMING  DIES 

In  their  simplest  form  trimming  dies  resemble  in  construction  and 
operation,  an  ordinary  shearing  or  cutting-off  die;  but  usually,  even  when 
made  for  merely  cutting  straight  across  the  work,  they  have  their  own 
peculiar  features,  particularly  in  reference  to  the  means  incorporated  for 
locating  the  piece  accurately  in  respect  to  other  cuts  already  taken,  and  for 
holding  the  work  during  the  trimming  process.  The  latter  feature  in  fact 


TRIMMING  DIES— TRIMMING  AND  SHAVING 


143 


occasionally  gives  the  trimming  die  a  closer  resemblance  in  appearance  to  a 
special  fixture  than  to  a  press  tool. 

The  photograph,  Fig.  183,  illustrates  a  case  in  point:  This  set  of  tools  is 
for  trimming  the  edge  of  a  machine  cover  which  has  been  passed  through  a 
number  of  press  operations  until  its  completion  requires  nothing  further 
than  the  cutting  off  of  the  edge  to  a  straight  line  a  certain  distance  from  the 


It 

/A    Screw 
/ 

I 

1 

<— 

-•-J 

>H- 

--»! 

-TTT:  /                     :  u  ; 

W           T-\ 

W-^                                                           !--•» 

,t 

r-r 

~n"      H  • 

ygj 

1                                               '              1 

I 

i 

[f 

if 

-/ 

t 

\ 

7 

> 

^ 
„ 

Ir 

* 

y//4     - 

. 

'2 

• 

FIG.  184.  —  Trimming  tools 


FIG.  185.  —  Dies  for  trimming  cams  from  a  disk 

point  where  the  bent  portion  meets  the  straight  lip.  The  work  rests  on  the 
die  upon  a  stop  surface  at  the  left  which  gives  it  the  desired  location  in 
reference  to  the  cutting  edge  and  it  is  here  secured  by  two  knurled  head 
clamp  screws  while  the  sheared  knife  edge  forming  the  punch  cuts  the  metal 
straight  across. 

The  sketch,  Fig.  184,  shows  the  manner  in  which  the  edge  of  the  cutting 
blade  is  cleared  for  side  shear  and  also  the  lengthwise  slope  which  gives  the 
cut  a  shearing  action  clear  across  the  work.  The  side  angle  is  7J  degrees 


144 


PUNCHES  AND  DIES 


and  the  lengthwise  slope  has  an  angle  of  2  degrees.  The  edge  of  the  die  or 
lower  member  of  the  set  of  tools  is  reduced  to  a  width  -of  about  TV  in.  as 
seen  in  the  photograph,  to  provide  a  concave  clearance  for  an  embossed 
surface  formed  along  the  work  under  the  pierced  holes.  The  cover  trimmed 
with  these  tools  is  9J  in.  long  and  it  is  made  from  cold  rolled  steel  0.040  in. 
thick. 


Dia.of  Dish 
Before  Trimming 

Right  &  Left 

Release  Cams 

Cold  Rolled  Steel 


FIG.  186.  —  Trimming  dies  for  a  small  cam 

A  TRIMMING  AND  SHAVING  JOB 

A  piece  of  work  involving  both  trimming  and  shaving  is  shown  in  Figs. 
185  and  186.  This  js  a  small  steel  cam  with  a  radius  from  center  to  point 
of  ^|  in.  It  is  used  on  a  calculating  machine,  and  it  forms  an  unusually 
interesting  application  of  the  trimming  principle,  for  the  blank  is  not  made 
from  sheet  stock  but  instead  is  produced  in  the  screw  machine  where  it  is 
turned  out  to  the  form  of  a  disk  0.080-in.  thick,  with  a  hub  finished  to 
0.280-in.  diameter,  and  a  hole  drilled  and  reamed  through  the  center  to 


TRIMMING  DIES— TRIMMING  AND  SHAVING 


145 


0.155  in.  Thus  in  the  shape  of  a  thin  disk  it  is  passed  through  the  press 
tools  for  the  making  of  the  cam  contour  instead  of  being  finished  by  the 
more  conventional  process  of  milling  to  shape. 

The  cam  is  made  both  right  and  left  hand,  one  each  being  required  for 
each  calculating  machine.  The  dies  are  correspondingly  made  for  right 
and  left-hand  lobes,  a  duplication  of  die  openings  made  necessary  by  the 
hub  extending  at  one  side  of  the  cam.  The  disks  are  placed  in  the  dies 
with  the  hub  located  in  the  round  end  of  the  opening  and  the  punch  upon 
descending  removes  all  of  the  superfluous  metal  around  the  cam  by  forcing 
the  latter  into  the  die.  The  cam  is  pressed  down  into  the  die  by  the  punch 
to  a  sufficient  distance  to  allow  the  next  blank  disk  to  enter  hub  down,  but 
with  the  lower  face  of  the  disk  resting  upon  the  face  of  the  die. 


FIG.  187.  —  Shaving  dies  for  a  small  cam 

The  construction  of  the  die  is  shown  clearly  in  Fig.  186.  The  die 
openings  are  located  at  a  distance  of  ItV  in.  apart  to  allow  two  blank 
disks  to  clear  one  another  when  placed  for  trimming  and  to  permit  of  the 
punches  being  made  separately  with  ample  size  of  base  for  stability.  The 
shape  of  the  punches  is  seen  in  the  detail  and  it  will  be  noticed  that  each  is 
made  with  a  base  1  by  1J  in.  in  area  and  secured  by  two  J-in.  fillister 
head  screws  and  two  dowel  pins  of  the  same  diameter. 

The  pressure  pad  and  stripper  carried  by  the  punch  head  is  fitted  closely 
to  the  punches  and  is  normally  held  downward  upon  the  work  when  the 
slide  descends  by  means  of  four  stiff  pressure  springs  located  at  the  corners 
on  yVin.  screws.  The  action  of  the  springs  and  plate  upon  the  upstroke 
is,  of  course,  to  strip  from  the  punches  the  trimmed-off  portion  of  the  disk 
left  in  the  making  of  the  cam. 


146 


PUNCHES  AND   DIES 


SHAVING  THE  CAMS 

These  trimming  dies  leave  about  0.003  in.  on  a  side  at  the  point  of  the 
cam  for  finishing  in  the  shaving  tools,  which  are  shown  by  Figs.  187  and 
188.  The  die  is  made  to  shave  two  cam  points  at  once,  one  right  and  one 
left-hand  and  the  work  is  placed  with  the  two  points  facing  each  other,  in 
which  position  each  cam  is  located  with  its  reamed  hole  fitting  over  a  pilot 


Tap  for    H   Scnew 


Via   Dowel 


4  Screws  5/16  Body 
4  Springs    %    Dia 

Locating  Pins 


3/^'  Fillister  Hd. 
Screw 


Dowel  Pin  Hole 


DETAIL  OF  NEST 
ONE  R.H.  ONE  L.H. 


FIG.  188.  —  Details  of  cam  shaving  dies 


pin  in  the  die  face  and  with  the  cam  body  lying  in  a  slot  in  the  nest  plate 
secured  to  the  die. 

[  n  The  cam  points  are  thus  positioned  to  allow  a  single  punch  with  shaving 
edges  on  opposite  sides  to  finish  both  cams  at  once. 

Details  of  punch,  die  nests,  and  pilot  pins,  spring  stripper,  etc.,  are 
all  brought  out  clearly  in  the  drawing,  which  should  require  no  further 
description. 


TRIMMING  DIES— TRIMMING  AND  SHAVING 


147 


Like  many  of  the  tools  illustrated  in  previous  chapters,  the  trimming 
and  shaving  dies  for  the  cams  and  those  that  follow  are  provided  with 
guide  pins  or  pillars  for  preserving  truth  of  alinement  with  consequent 
accuracy  and  longevity  in  operation. 

ANOTHER  TRIMMING  AND  SHAVING  DIE 

The  steel  piece  in  the  foreground  of  Fig.  189  is  another  example  of 
trimming  and  shaving  work,  which  is  shown  in  detail  in  Fig.  190.  This 
small  lever,  which  is  blanked  from  half  hard  steel  stock,  is  0.140-in.  thick 
and  prior  to  reaching  the  dies  in  Figs.  189  and  191  it  has  been  shaved  all 
the  way  around  and  pierced  in  separate  press  operations.  Both  shaving 


FIG.  189.  —  Trimming  and  shaving  cams  for  a  small  lever 

and  piercing  dies  are  illustrated  at  another  point  in  this  book.  See  Figs. 
94  and  182.  The  heel  of  the  lever  and  the  point  have  been  milled  down 
to  dimensions  given  and  the  object  of  the  operations  in  the  present  dies  is 
to  trim  the  round  end  to  an  angle  at  A  and  shave  it  accurately. 

The  die  is  so  made  that  the  right-hand  side  of  the  opening,  Fig.  191, 'is 
adapted  for  trimming  the  work  to  form  the  V  point,  while  the  opposite  side 
is  for  the  shaving  operation,  as  indicated  in  the  plan  view.  The  blank,  No. 
1,  at  the  right  is  shown  as  it  appears  after  trimming,  and  the  other  piece, 
No.  2,  occupies  the  shaving  position.  After  the  latter  is  removed  the  blank 
at  the  right  side  is  transferred  to  the  left  and  a  fresh  blank  placed  in  position 
1  for  trimming.  Thus  at  each  stroke  of  the  press  one  piece  is  trimmed  and 
another  shaved.  The  latter  operation  removes  about  0.010  in.  of  metal 
from  each  side  of  the  angular  point. 


148 


PUNCHES  AND   DIES 


SECTION  OF  DIE 

WITH  WORK  SHOWN 

ON  ONE  SIDE  ONLY 

FlG.191 


End    A    to  be  Trimmed 
A         and  Shaved 

\/<  ^V 


DO     ) 


The  Blank 
for  Trimming 
and  Shaving 


Cut  Edge^   ,-- 


3S/64  Rad.   .230  Deep 


*43  Dr. 
*42  Ream 


LJi; 


.290 


_  22  Ream 

«.L"  Note:  Angle  Layout  from 
.125  Point.  Break  Point 
with  .007  Sad. 


BACK  VIEW 


6  Levers  for  Med.  Mach 

I-EFT  S|DE  FRONT  RIGHT  SIDE 

Transfer  Lever.  12  Req.  .145.x  2l/4*H.  Hard  Stock. 
FIGS.  190-191.  —  Trimming  and  shaving  tools  for  a  small  lever 


TRIMMING  DIES  — TRIMMING  AND  SHAVING  140 

The  method  of  holding  the  work  at  each  side  of  the  die  is  to  slip  it  over 
two  locating  pins  which  fit  the  small  round  hole  at  the  end  and  the  oblong 
opening  in  the  head  of  the  work,  and  then  swing  the  eccentric  binder  B  by 
the  small  handle  to  secure  the  piece  in  place. 

The  punch  is  illustrated  in  plan  and  by  several  elevations.  It  has  two 
guiding  extensions  CC  which  are  J  in.  longer  than  the  cutting  face  and 
which  enter  the  corresponding  guide  openings  C'C'  in  the  die  to  that  depth 
before  the  cut  is  started.  The  shoulders  DD  fitting  between  sides  D'D'  in 
the  die  still  further  steady  the  punch  for  the  trimming  and  shaving  cuts. 


FIG.  192.  —  A  piercing  and  trimming  die 

The  pressure  pad  or  stripper  fitted  over  the  punch  is  controlled  by  four 
springs  under  the  corners  as  shown  clearly  by  Fig.  189. 

DIES  FOB  PIERCING  AND  TRIMMING 

Another  form  of  shaving  die  combined  with  piercing  tools  is  illustrated 
in  Figs.  192  and  193  for  operations  on  the  two  rocker  arms  shown  in  Fig. 
194.  These  two  steel  pieces  are  blanked  from  ^\-in.  stock  and  are  alike 
as  they  come  from  the  blanking  dies.  The  trimming  and  piercing  dies  in 
the  above  engravings  are  then  used  for  piercing  one-half  of  the  lot  of  rocker 
arms  as  at  X,  Fig.  194,  and  for  trimming  off  and  piercing  the  other  half  of 
the  lot  to  make  the  shorter  piece  Y. 

The  drawing  of  the  die  and  punch  plate  in  plan  view  shows  the  method 
of  placing  two  blanks  at  once  in  the  nests  on  the  die  face,  and  the  notation 
on  the  views  indicates  the  operation  performed  by  each  punch  and  die  in 
the  set. 

Thus  the  trimming  punch  A'  trims  off  the  end  of  one  of  the  rocker  arms 
at  A,  the  portion  removed  being  indicated  by  dotted  lines.  The  punch  Bf 


150 


PUNCHES  AND  DIES 


and  die  B2  pierce  the  hole  B\  the  punch  Cf  and  die  C2  pierce  the  larger  hole 
C.  The  rocker  arm  X  at  the  left  is  pierced  by  punches  Df  and  Er  which 
act  with  dies  D2  and  E2  to  form  the  holes  D  and  E.  The  end  of  the  work 
in  this  side  of  the  die  is  not  trimmed  but  is  left  to  the  blanked  size. 

?«.  Piercing  Die  for  Hole  E  D^Piercine  Punch  for  Hole  D 

D2 -Piercing  Die  for  Hole  D 
*- Piercing  Die  for  Hole  B 

Trimming  Punch  for  End  A 


Piercing  Punch  for  Hole  B 
C- Piercing  Punch  for  Hole    (7 
£71  Piercing  Punch  for  Hole  E 


C7-Piercing  Die  for  Hole  C 


FIG.  193.  —  Trimming  and  piercing  die 


>  n        Turn  4,  Polish  End  8/i6  Back 

Slot  A  WliM*  Rad. 
Bevel  R.  &  L.  on  Rad.        13," 
to  Rive 


3, Kad 


C'sk. 


1  R.&  1  L.Side 


*42  Drill 


Ream  .218 


C'sk  1  R.&  1  L.Side   l/g,    Diana. 


Long  Rocker  Arm.  2  Req.   /gj   Stock  x 
2h"wide.  H.Hard.  Case  Hard.  Point. 


Short  Rocker  Arm.  2  Req.  Blank 

Same  as  Long  Arm.  &  Trimm.  &  Pierce, 

FIG.  194.  —  Rocker  arm  detail 


The  trimming  punch  A',  it  will  be  noticed,  enters  into  and  is  guided  by 
the  slotted  opening  A 2  in  the  rear  of  the  die.  It  performs  its  work  before 
the  piercing  punches  enter  the  blanks.  The  die  hole  B2  for  this  end  of 
the  short  rocker  arm  is  formed  in  the  trimming  die  itself,  as  shown  by  the 
half-tone,  Fig.  192,  but  the  other  piercing  dies  are  in  the  form  of  bushings 
which  are  inserted  in  the  die  plate  where  they  are  represented  by  dotted 
and  full  line  circles. 


TRIMMING  DIES— TRIMMING  AND  SHAVING 


151 


The  nests  for  the  two  pieces  worked  in  these  dies  are  made  up  of  three 
plates  L,  M,  and  N,  which  are  secured  by  screws  and  dowels  to  the  die  face. 
These  nest  plates  are  made  to  match  the  straight  edges  of  one  side  of  the 
work  and  the  tapered  edge  on  the  opposite  side.  The  wide  center  of  the 
work  is  blanked  to  a  radius  of  |f  in.  and  this  circular  portion  fits  into  a 
similarly  shaped  seat  in  the  edges  of  the  middle  nest  plate  M  to  locate  the 
piece  endwise^ 

APPLICATION  OF  THE  " KNOCK-OUT" 

Where  work  of  irregular  outline  and  slender  proportions  is  to  be  trimmed 
by  forcing  it  down  into  a  die,  leaving  the  trimmed  scrap  or  rim  on  the  die 
surface,  it  is  advisable  to  use  a  knock-out  to  eject  the  trimmed  piece  from 


(T.S.  Bushing  Harden  &  Grind. 
Drill  &  R*am  for  5/  (V  Harden, 
Dowel  Pin 


6771  Make  Die  of  Jessops 

, ,       Punch  of  Bethlehem  Tool  Boom  Steel* 
„      Pad  of  M.8.  Case  Harden 

Keep  Distance 
.125 


FIG.  195.  —  Trimming  die  for  a  curved  part 

the  top  of  the  die  to  avoid  possibility  of  the  work  becoming  clogged  or 
stacked  in  the  die  and  injured  by  bending. 

An  illustration  of  a  die  of  this  character  is  presented  in  Fig.  195  here- 
with. It  is  for  trimming  a  typewriter  type  bar  which  has  a  long,  slender, 
and  crooked  body  well  adapted  to  give  trouble  in  any  effort  to  pass  it 


152  PUNCHES  AND   DIES 

through  an  open  trimming  die.     So  the  die  is  made  as  illustrated  with  a 
knock-out  which  ejects  the  work  after  the  trimming  operation. 

The  outline  and  dimensions  of  the  type  bar  will  be  seen  from  the  draw- 
ing. The  arrangement  of  knock-out  and  stripper  are  equally  clear,  but 
brief  reference  may  be  made  to  certain  features.  The  knock-out  is  operated 
by  a  rubber  spring  of  liberal  proportions  under  the  die  base  and  two  pins  at 
AA  serve  to  connect  the  knock-out  and  spring.  The  knock-out  is  made 
to  have  sV-in-  clearance  all  the  way  around  in  the  trimming  die  and  its 
flanged  base  fits  up  into  the  under  side  of  the  die  as  illustrated  by  the  cross 
section.  The  stripper  is  an  open  end  affair  bolted  to  the  right-hand  end  of 
the  die. 

OPERATIONS  ON  A  TUBE 

Sometimes  dies  are  required  for  trimming  the  ends  of  round  and  square 
tubing  where  a  half  round  or  other  shape  of  opening  is  wanted,  and  an 
example  of  a  piece  of  work  of  this  character  is  presented  in  Fig.  196. 

The  tube  is  of  brass,  2  in.  square,  and  requires  a  concave  cut  to  be 
taken  at  each  side  as  shown  at  C.  This  concave  portion  is  formed -to  a 
radius  of  2J  in.  and  the  depth  of  cut  from  the  end  of  the  tube  is  about 
A  in. 

The  trimming  die  consists  of  a  die  proper  at  D  set  into  the  shoe  E,  the 
die  being  made  with  a  2j-in.  opening  to  correspond  with  the  diameter  of 
the  punch  F.  The  block  G  is  secured  to  the  die  shoe  to  carry  the  stripper 
H  and  is  bored  out  to  form  a  support  for  backing  up  the  punch  which  slides 
closely  in  the  guide  bored  in  G.  Block  G  is  planed  out  to  form  a  rectangu- 
lar opening  in  front  for  the  square  tube  to  enter  and  when  the  work  is 
slipped  into  place  it  rests  with  its  inner  end  against  the  flattened  face  of 
the  trimming  punch  at  F. 

The  punch  is  cut  back  for  its  entire  length  except  for  a  portion  about 
f-in.  wide  which  is  left  with  its  original  circle  as  a  cutting  edge  for  trimming 
out  the  concave  end  of  the  work.  In  operation  the  tube  to  be  trimmed  is 
placed  as  indicated  with  the  flattened  portion  of  the  punch  face  for  a  stop 
and  then  the  lower  side  of  the  tube  is  trimmed  to  the  desired  concave. 
Then  the  tube  is  turned  half  over  and  the  operation  repeated  for  the  second 
side. 

ADJUSTABLE  TRIMMING  AND  SHAVING  DIES 

Reference  has  been  made  in  the  foregoing  pages  to  the  possibility  of 
using  trimming  dies  for  cutting  blanks  of  uniform  pattern  to  different 
lengths  in  order  to  save  duplication  of  blanking  dies  for  each  and  every 
different  size  of  piece  in  the  series.  An  illustration  of  this  principle  is  con- 
tained in  the  views  that  follow,  which  show  the  method  of  blanking,  trim- 
ming, and  shaving  a  set  of  nine  steel  cams  for  a  calculating  machine,  these 
cams  varying  in  length  throughout  the  group  of  nine  parts.  Only  one 


TRIMMING  DIES— TRIMMING  AND  SHAVING 


153 


set  of  blanking  tools  is  required,  and  one  second  operation  die  accomplishes 
the  trimming  and  shaving  of  the  entire  lot  of  cams. 

Three  of  the  set  of  nine  cams  are  shown  in  detail  in  Fig.  197  and  the 


table  at  the  side  gives  the  variation  of  all  of  the  cams  in  the  series  as  indi- 
cated by  the  number  of  degrees  from  the  center  line  to  the  top  of  the  cam 
riser  near  each  end.  Thus  the  range  for  the  cams  is  from  50  degrees  down 
to  10  degrees  as  measured  from  center  to  point  of  throw.  The  cam  ends 


154 


PUNCHES  AND  DIES 


at  the  arc  A  are  all  alike  and  this  arc  is  struck  from  a  radius  of  0.570  in. 
in  all  cases.  This  makes  it  possible  to  utilize  one  trimming  die  for  all  sizes 
of  cams,  as  the  portion  operated  upon  in  finishing  the  blank  is  uniform 
throughout  the  series  of  cams. 

The  blanking  tools  are  seen  in  Figs.  198  and  199  and  the  latter  shows 
the  method  of  locating  the  stock  gage  so  that  it  drops  into  the  opening  in 


41  Holes    for  Rivets 


G-16 


9  CAMS  IN  SERIES  /0*  R-  i  7       " 

G-i4  i«ii  4i-*»«JSaT  J^sfe 


G-15 

, 

=  45 

T7-OOU1 

•  •  \  //;   x 

G-16 

tj 

=  40 

$% 

G-l-7 

=  35 

*  A^ 

-W^1 

G-18 

=  30 

/wi-cL-i: 

G-19 

=  25 

%"  R: 

/X^jpJ^ 

G-20 
G-21 
G-22 

=  20 
=  15 
•  =10 

Fr.  .5 
Arc 

7°>oi      01 

/*lo>f<lo^ 

Grind 
,115" 


G-22 

STEEL  CAMS 
FIG.  197.  —  Details  of  three  cams  of  a  set  of  nine 

the  scrap  immediately  ahead  of  the  blank  that  is  being  punched  out.  The 
stop  is  of  the  trigger  type  with  projecting  end  for  operation  by  the  adjust- 
able striking  screw  in  the  punch  head  when  the  latter  descends.  At  the 
right  is  a  spring  actuated  pressure  finger  for  holding  the  heavy  stock 
closely  to  the  back  guide  under  the  stripper.  It  will  be  noted  that  this 
stock  is  0.120-in.  half  hard  steel. 


TRIMMING  DIES— TRIMMING  AND  SHAVING 


155 


FIG.  198.  —  Cam  blanking  dies 


Spring      i      ?"•  '  Spring  Stock         Flat  Spring 
for  'Trigger  Stop  Finger 


FIG.  199.  —  Cam  blanking  die 


156 


PUNCHES  AND  DIES 


CONSTRUCTION  OF  TRIMMING  DIE 

The  trimming  dies  (which  are  also  used  for  the  shaving  operation)  are 
shown  by  Figs.  200  to  205  inclusive.  In  the  first  of  these  views  the  entire 
series  of  nine  cams  of  different  lengths  are  shown  in  the  foreground  and  the 
locating  nest  is  seen  empty  with  three  knock-out  pins  projecting  slightly 
above  the  bottom  of  the  work  seat  just  as  they  are  thrown  up  by  the  handle 
in  front  when  the  trimmed  cam  is  ejected.  In  Fig.  201  the  middle  length 
of  cam,  No.  18,  as  it  is  called,  is  seen  in  position  in  the  nest  which  is  here 
shown  adjusted  around  to  central  position.  In  the  preceding  view,  Fig. 
201,  this  locating  nest  is  seen  at  the  extreme  right-hand  position  or  in  the 


FIG.  200.  —  Trimming  and  shaving  dies  for  a  bteel  cam 

place  in  which  it  is  set  for  the  longest  cam  of  the  series,  namely,  No.  14. 
In  Fig.  202  the  graduations  at  the  front  of  the  die  for  giving  the  nine  posi- 
tions for  all  of  the  cams  are  plainly  seen. 

It  will  be  gathered  from  these  views  that  this  die  is  arranged  to  take 
the  same  cut  on  all  of  the  cams,  that  is  to  give  the  ends  of  all  cams  the  same 
form;  but  each  number  of  cam  is  cut  to  a  different  length  from  the  other 
cams  in  the  series,  so  that  more  metal  is  trimmed  off  from  some  cams  than 
from  others,  the  amount  removed  varying  with  each  cam  member. 

Referring  now  to  Fig.  203,  this  drawing  shows  at  A  a  half  round  lug  on 
the  locating  device  B  which  is  used  for  positioning  all  lengths  of  cams  from 


TRIMMING  DIES— TRIMMING  AND  SHAVING  157 


FIG.  201.  —  Trimming  and  shaving  dies  for  steel  cams 


m  i 


FIG.  202.  —  Face  of  cam  die 


158 


PUNCHES  AND  DIES 


the  similar  notch  blanked  in  their  concave  sides.  According  to  the  detail, 
Fig,  197,  this  locating  notch  is  made  to  a  radius  of  «&  in.  and  is  0.070  in. 
deep.  When  the  adjustable  nesting  device  B  is  set  by  the  front  gradua- 
tions C  to  the  right  position,  the  cam  placed  in  the  nest  will  be  cut  off  to 
desired  length  and  form.  After  the  entire  lot  for  one  length  of  cam  has 
been  trimmed,  the  device  B  is  reset  to  another  graduation  C  and  the  next 
length  trimmed,  and  so  on.  This  is  brought  out  distinctly  by  the  sketches, 
Figs.  204  and  205,  which  show  the  settings  for  two  cams,  one  long  and  one 

Cutting  Portion  of  Punch 


r          !  for  Setting  Work  Loc'ating^ 

I  I  !  Device    B      \  I 


Clearance  for  Grinding1 
Punch 


Locat 
for  Cam 

to  be 
Trimmed 

Position  of  Locating 
Device  for  Long  Cam 


Position  of  Locating 
Device  for  Short  Cam 


FIG. 203 
FIGS.  203-205. 


Fic.204  FIG.  20  5 

Trimming  and  shaving  dies  for  steel  cams 


short,  and  indicate  the  amount  of  movement  of  device  B  in  the  change 
from  one  cam  to  the  other.  The  intermediate  settings  possible  are  all 
established  by  the  graduations  on  Plate  C  let  into  the  front  of  the  die 

shoe 

THE  CUTTING  EDGES 

The  front  end  of  any  cam  trimmed  in  this  die  is  located  against  stop 
gage  D  and  as  the  blank  cam  rests  closely  in  the  circular  channel  or  nest  E 


TRIMMING  DIES— TRIMMING  AND   SHAVING  159 

with  its  half  round  notch  over  the  lug  A,  the  work  is  well  secured  against 
shifting  under  the  cut.  This  notch  by  the  way  is  the  locating  medium  for 
the  finished  cam  when  assembled  in  the  calculating  machine,  hence  the 
importance  of  finishing  all  ends  from  this  central  point.  Both  ends  of 
each  cam  are  trimmed  alike,  the  blank  being  turned  over  for  the  cut  on  the 
opposite  end. 

The  trimming  punch  has  only  a  short  length  of  cut  but  is  itself  of  liberal 
proportions  for  rigidity.  It  fits  at  back  and  sides  in  the  oblong  die  opening 
which  acts  as  a  further  guide  for  retaining  the  punch  in  alinement.  The 
back  of  the  punch  as  indicated  at  F  is  J-in.  longer  than  the  face  so  that  it 
has  an  opportunity  to  become  well  located  in  the  die  opening  before  the 
cutting  edge  strikes  the  work.  The  punch  is  enclosed  in  the  spring  con- 
trolled stripper  and  pressure  pad  G  which  holds  the  blank  firmly  during  the 
trimming  operation. 

In  operation,  the  die  is  first  set  for  trimming  the  cams  to  specified  length 
by  bringing  the  vertical  zero  line  0  (on  the  wing  under  locator  B)  to  within 
aV  in.  of  the  required  graduation  on  scale  C.  This  offset  is  enough  to 
allow  the  dies  to  trim  the  cams  longer  than  finish  size  by  about  0.010 
in.  which  amount  is  left  for  shaving  in  a  second  operation  in  the  same 
dies.  For  the  shaving  cut,  which  is  taken  after  the  entire  lot  have  been 
trimmed  as  above,  the  locating  device  B  is  reset  exactly  to  the  requisite 
graduation  and  the  work  run  through  as  before  for  the  removing  of  the 
thin  chip  which  smooths  the  cam  ends  perfectly  and  brings  them  to  exact 
length. 

TRIMMING  AND  SHAVING  DIES  OF  THE  PROGRESSIVE  ORDER 

There  is  one  more  type  of  die  that  should  be  of  interest  in  this  chapter  — 
the  progressive  trimming  and  shaving  arrangement  illustrated  by  Figs.  206 
to  208.  These  tools  are  for  the  manufacture  of  a  small  calculating  machine 
key  of  the  dimensions  given  on  the  part  detail  in  the  latter  engraving.  The 
material  used  is  steel  lengths  about  |-in.  wide  by  0.078-in.  thick.  The 
dies  perform  their  work  by  cutting  away  the  material  from  one  side  only, 
thus  producing  the  piece  complete  by  the  trimming  and  shaving  process. 

The  small  key  is  finished  0.458-in.  long  and  has  a  projection  at  one 
side  0.015-in.  high  by  0.090-in.  wide.  The  method  of  running  the  stock 
through  the  dies  will  be  understood  upon  examination  of  the  plan  views  of 
the  tools  in  Figs.  207  and  208. 

The  material  is  fed  in  through  the  narrow  channel  guide  at  the  right  of 
the  die  openings  and  with  the  first  stroke  of  the  press  the  trimming  punch 
A  takes  a  cut  along  the  edge  indicated  at  Al.  At  the  next  advance  of  the 
stock,  the  portion  already  trimmed  is  shaved  as  at  edge  J51  by  the  punch 
B,  and  the  trimming  punch  A  operates  on  the  next  "cut.  At  the  same 
stroke,  the  extension  C  on  the  shaving  punch  B  cuts  off  the  key  at  the  point 


160 


PUNCHES  AND   DIES 


FIG.  206.  —  Trimming  and  shaving  dies  in  progressive  order 


V. 

< 


FIG.  207.  —  View  of  punch  and  die  face 


TRIMMING  DIES— TRIMMING  AND    SHAVING 


161 


Cl  and  when  the  work  is  advanced  to  the  third  position  the  end  of  the  key 
is  trimmed  by  the  punch  D  and  die  Dl.  Each  succeeding  stroke  of  the 
press  then  causes  one  portion  of  the  stock  to  be  trimmed  closely  to  the  key 
width,  the  preceding  portion  to  be  shaved  to  size  and  cut  off,  and  the  leading 
end  of  that  piece  to  be  shaved  to  length. 

SOME  DETAILS  OF  CONSTRUCTION 

The  drawing,  Fig.  208,  shows  the  principal  features  of  the  tools  but 
certain  details  are  best  seen  in  the  photographic  views,  particularly  the  air 


SEQUF.NCE  OF  CUTS 

FIG.  208.  —  Progressive  trimming  and  shaving  die 

nozzle  and  control  for  blowing  the  finished  blank  from  the  dies.  The 
narrow  strip  of  stock  is  pressed  back  to  the  guide  by  the  spring  actuated 
ringer  F  at  the  front,  this  being  shown  by  dotted  lines  in  the  plan  view  of 
the  die  in  Fig.  208.  At  G  is  a  small  knock-out  pin  which  is  operated  by  a 
wedge-shaped  member  underneath  to  lift  the  finished  work  slightly  and  so 
allow  the  compressed  air  charge  to  blow  the  piece  clear  off  the  dies.  The 
wedge  for  operating  this  is  itself  moved  forward  against  spring  pressure  by 


162  PUNCHES  AND  DIES 

a  pivoted  latch  H,  Fig.  206,  which  is  carried  on  a  vertical  arm  I  adapted 
to  operate  in  tube  /  at  the  rear  of  the  die.  The  pivoted  piece  H  on  the 
down  stroke  rocks  up  sufficiently  to  swing  past  the  end  of  the  operating 
wedge  and  on  the  ascent  of  the  punch  it  drops  back  to  its  seat  and  acts 
against  the  end  of  the  wedge  which  then  slides  forward  and  operates  the 
knock-out  pin  G,  Fig.  208. 

The  air  nozzle  is  controlled  by  the  plunger  K,  Fig.  206,  and  the  hooked 
finger  L  on  the  punch  head  which  acts  upon  the  plunger  head  when  the 
punch  rises  with  the  press  slide.  The  stop  for  the  first  position  of  the 
stock  is  operated  by  lever  M,  and  the  second  stop  by  lever  N. 

THE  FORM  OF  THE  PUNCHES 

The  different  views  show  clearly  the  form  of  the  punches  and  stripper, 
as  well  as  the  die  itself  which  is  made  in  halves  to  facilitate  construction. 
The  trimming  and  shaving  punches  0  and  P  are  of  different  height 
of  cut  so  that  the  trimming  tool  does  its  work  before  the  shaving  die 
strikes  the  stock.  Both  punches,  and  the  end  punch  Q  as  well,  are  made 
with  back  portions  extended  downward  sufficiently  to  enter  the  guides 
formed  by  the  die  openings  before  the  cutting  portion  contacts  with  the 
work.  The  cutting  edges  are  cleared  as  shown  and  the  relief  along  the 
center  of  each  punch  end  enables  the  tools  to  be  ground  readily. 

Another  set  of  dies  of  this  same  construction  are  used  for  trimming  and 
shaving  a  longer  key  and  here  the  punches  are  sheared  from  end  to  end  to 
enable  them  to  take  the  longer  cut  easily  and  with  smoothest  possible 
results.  The  shearing  angle  on  these  cutting  edges  is  about  3  degrees. 

The  pressure  pad  and  stripper  for  the  punches  shown  is  backed  up  by 
very  heavy  springs  at  the  four  corners  and  the  pad  face  is  milled  away  as 
represented  to  leave  a  narrow  bearing  surface  along  the  face  for  contact 
with  the  work.  This  holds  the  narrow  stock  strip  securely  against  possi- 
bility of  rocking  during  the  taking  of  the  cuts  along  the  one  edge. 


CHAPTER  VIII 
DRAWING  DIES   AND  THEIR  ACTION  UPON   MATERIALS 

Press  tools  of  this  class,  while  used  in  almost  infinite  form  and  variety, 
are  frequently  found  to  be  most  difficult  to  make  for  entirely  satisfactory 
operation.  There  are  several  factors  entering  into  their  use  that  have  less 
weight  with  other  classes  of  dies  and  which  cause  each  set  of  drawing  dies 
to  be  more  or  less  of  an  individual  problem  for  the  tool  maker. 

In  the  first  place,  the  character  and  quality  of  the  material  to  be  worked 
is  an  element  of  greater  importance  than  with  the  majority  of  press  tools 
and  a  set  of  drawing  dies  which  might  give  perfect  results  with  one  grade 
of  stock  may  be  found  anything  but  satisfactory  when  applied  to  another 
kind  of  material.  The  thickness  of  the  metal  is  another  factor  that  must 
be  given  unusual  consideration  for  it  has  a  most  direct  bearing  upon  the 
form  that  is  to  be  given  the  edge  or  mouth  of  the  drawing  die.  the  radius 
of  the  corner  at  the  drawing  edge  being  usually  based  to  a  large  degree, 
if  not  wholly,  upon  the  gage  of  the  stock  to  be  drawn. 

The  division  of  the  total  length  or  depth  of  draw  into  a  suitable  num- 
ber of  intermediate  operations  is  another  feature  of  the  problem.  A  shal- 
low draw  is  one  proposition;  a  deep  draw  another.  The  character  of  the 
metal  worked  is  a  determining  factor  here  and  the  total  number  of  draws 
and  the  corresponding  number  of  tools  in  the  entire  outfit  is  a  matter  that 
is  quite  apt  to  be  settled  in  accordance  with  the  experience  of  the  die  maker 
who  has  the  work  in  hand.  With  his  knowledge  of  the  limitations  of 
various  grades  of  stock  he  is  enabled  to  arrive  at  results  that  cannot,  as  a 
rule,  be  obtained  by  merely  following  a  layout  that  may  or  may  not  seem 
properly  proportioned. 

LIMITING  FACTORS 

If  the  attempt  be  made  to  draw  the  metal  to  too  great  a  depth  in  each 
operation  the  material  will  be  fractured  or  the  bottom  of  the  shell  torn  out. 
If  the  radius  of  the  drawing  die  edge  is  too  small  the  metal  will  be  drawn 
too  abruptly  over  the  corner  with  probability  of  becoming  stressed  beyond 
its  tensile  strength  and  ruptured.  If,  on  the  other  hand,  the  radius  be  too 
great  the  surface  of  the  work  is  likely  to  become  wrinkled  in  the  drawing 
process  due  to  the  failure  of  the  material  to  cling  to  the  drawing  surface. 
With  the  heavier  gages  of  stock  there  can  be  corresponding  increase  in  the 
radius  of  the  drawing  edge  because  of  the  tendency  for  the  thicker  metal  to 
hold  closer  to  the  drawing  surface. 

163 


164  PUNCHES  AND  DIES 

If  too  little  allowance  is  left  between  first  operation  drawing  punch  and 
die  diameters,  unsatisfactory  results  may  be  expected,  for  in  such  case  the 
shell  is  likely  to  be  fractured,  and  the  wear  on  the  die  surface  seriously 
increased,  with  the  result  that  it  becomes  scratched  and  pitted  through 
consequent  improper  lubrication,  and  the  work  is  drawn  with  a  scratched 
surface.  If  the  depth  of  the  drawing  surface  in  the  die  is  too  great  similar 
results  will  be  produced.  These  are  some  of  the  considerations  affecting 
punch  and  die  construction  for  drawing  operations,  and  they  will  be  dealt 
with  more  fully,  along  with  other  features  of  importance,  as  this  chapter 
develops. 

ACTION  OF  THE  TOOLS  UPON  THE  WORK 

It  is  not  always  easy  to  analyze  the  action  of  drawing  dies  and  the  de- 
tailed effect  of  the  drawing  process  upon  the  material.  The  following 
sketches  may  be  of  aid  in  this  direction  however. 

Suppose  we  have,  for  example,  a  3-in.  disk  of  brass,  A,  Fig.  209,  which 
is  to  be  drawn  in  a  single  operation  (for  simplicity  of  illustration)  to  the 
shell  form  at  J5,  which  has  a  depth  of  1J  in.  and  a  diameter  measured  at 
the  center  of  the  thickness  of  the  wall  of  If  in.  These  are  the  propor- 
tions to  which  such  a  blank  would  draw  if  no  allowance  be  made  for  stretch 
in  the  stock  and  if  the  corners  were  square.  Now  let  us  consider  what  the 
combined  effect  of  the  punch  and  die  will  be  when  the  round  blank  is  pushed 
down  through  the  die,  or  " drawn,"  as  we  say,  into  the  shell  B. 

The  punch  we  will  consider  as  made  smaller  than  the  inside  diameter 
of  the  die,  by  an  amount  equal  to  twice  the  thickness  of  the  metal  to  be 
drawn,  so  that  the  latter  will  have  space  to  retain  its  original  thickness. 
The  central  portion  of  the  blank,  then,  for  a  diameter  equal  to  the  size  of 
the  die  opening,  will  be  started  down  into  the  die  much  as  though  it  were 
being  punched  out  by  a  piercing  punch  except  that  the  round  corners  of  the 
punch  and  die  and  the  liberal  side  clearance  between  the  two  tools  will  pre- 
vent the  center  from  being  cut  out,  and,  as  the  punch  continues  to  descend, 
all  of  the  metal  in  the  blank  surrounding  the  central  portion  will  be  caused 
to  follow  down  through  the  die  and,  in  doing  so,  to  flow  along  radial  lines 
until  the  complete  area  of  the  ring  of  stock  outside  of  the  center  which 
forms  the  bottom  of  the  shell  has  been  absorbed  into  the  side  walls  of  the 
shell. 

DISPLACEMENT  OF  THE  METAL 

The  effect  of  this  drawing  process  upon  the  structure  of  the  blank  disk 
of  metal  may,  to  a  limited  extent  at  least,  be  seen  by  reference  to  Fig.  210. 
Suppose  that  here  we  have  placed  a  number  of  narrow  strips  of  stock,  C,  C, 
C,  which  are  of  so  light  a  gage  that  their  thickness  may  be  disregarded  for 
the  moment.  These  strips  are  spaced  uniformly  in  a  seat  or  nest  at  the  top 
of  the  die  and  their  width  is  such  that  their  edges  intersect  at  a  distance 
from  the  center  equal  to  the  radius  of  the  die  opening  below,  which  is  here 


DRAWING  DIES  AND  THEIR  ACTION  UPON  MATERIALS       165 


E 


FIG, 212  FIG.  211 

FIGS.  209-212.  —  Action  of  drawing  dies 


166  PUNCHES  AND  DIES 

indicated  by  the  dotted  circle  D.  The  punch  is  then  allowed  to  descend 
and  in  so  doing  it  forms  up  the  series  of  crossed  strips  of  metal  into  the 
shell  in  Fig.  211  where  the  vertical  walls  of  the  piece  are  composed  of  the 
formed  up  ends  of  the  strips  which  are  shown  as  abutting  against  one  an- 
other. '  As  these  strips  are  bent  down  over  the  drawing  edge  of  the  die 
and  pressed  down  through,  their  ends  approach  the  die  diameter,  and, 
traveling  along  radial  lines,  their  facing  corners  E,  E,  converge  and  the 
triangular  space  F  between  them  grows  smaller  until  it  disappears  com- 
pletely with  the  arrival  of  the  ends  of  the  strips  at  the  die  opening  upon 
the  completion  of  the  down  stroke  of  the  drawing  punch. 

APPLICATION  TO  THE  SOLID  DISK 

If  we  now  transfer  the  pattenn  made  up  of  the  narrow  strips  in  Fig.  210 
to  the  plain  disk,  Fig.  209,  and  trim  out  the  V  sections  between  the  lines, 
we  obtain  a  spider  effect,  Fig.  212,  with  a  center  the  size  of  the  die  and 
sixteen  .radiating  arms.  This  blank  may  then  be  forced  through  the  dies 
and  formed  into  the  same  shape  as  the  crossed  strips,  or  again  as  repre- 
sented by  Fig.  211.  But  the  process  is  not  one  of  drawing,  for  no  metal 
has  been  displaced  or  caused  to  flow  under  tension,  and  the  shell  wall 
formed  by  the  series  of  vertical  arms  on  the  blank  is  merely  the  result  of  a 
forming  or  bending  operation  accomplished  in  the  drawing  die. 

But,  upon  taking  the  plain  disk,  Fig.  209,  and  comparing  its  area  with  that 
of  the  spider  in  Fig.  212  and  then  forcing  the  former  through  the  drawing 
die  we  are  enabled  to  arrive  at  some  conclusion  as  to  the  effect  upon  the 
blank  under  the  drawing  process.  In  this  particular  instance,  the  amount 
of  material  cut  out  of  the  blank  in  Fig.  212  will  equal  about  2  sq.  in. 
or  roughly  30  per  cent  of  the  original  area  of  the  plain  disk.  Therefore 
if  this  plain  disk  is  drawn  up  as  in  Fig.  209,  the  above  area  of  2  sq.  in., 
times  the  thickness  of  the  stock  is  the  amount  of  metal  that  has  to  be 
displaced  by  the  flowing  under  tension  and  absorbed  into  the  mass  of  the 
shell  during  the  drawing  operation. 

The  30  per  cent  of  material  thus  accounted  for  represents  an  exagger- 
ated condition,  in  order  that  emphasis  may  be  placed  upon  the  peculiari- 
ties of  the  drawing  process ;  under  usual  practice  the  first  drawing  operation? 
or  the  " cupping"  so-called,  from  the  blank  to  the  first  short  shell  or  "cup" 
is  not  designed  to  produce  a  height  of  side  wall  of  much  over  one-half  the 
diameter  of  the  shell,  especially  if  the  metal  is  tV  m-  or  more  in  thick- 
ness. Therefore,  if  in  approaching  more  closely  to  normal  conditions  we 
cut  down  the  diameter  of  the  blank  to,  say,  about  2-fg  in.  (which  would 
be  the  approximate  size  for  a  shell  drawn  to  If  in.  diameter  by  f  in.  high) 
we  shall  find  that  the  excess  of  metal  to  be  absorbed  into  the  body  of  the 
shell  as  drawn  through  the  die  is  only  about  one-half  the  above  propor- 
tion, or  15  per  cent. 


DRAWING  DIES  AND  THEIR  ACTION  UPON  MATERIALS       167 

THE  LINES  OF  MOVEMENT 

As  already  pointed  out,  the  flowing  of  the  metal  in  the  blank  disk, 
when  subjected  to  the  tension  imparted  by  the  drawing  tools,  is,  generally 
speaking,  along  radial  lines;  although  there  would  necessarily  appear  to  be 
an  accompanying  lateral  or  annular  flow  throughout  the  body  of  the  shell, 
particularly  where  the  punch  and  die  are  so  made  as  to  leave  a  space  be- 
tween their  surfaces  equivalent  only  to  the  thickness  of  the  stock.  The 
result  is  a  more  densely  compressed  material  with  corresponding  hardening 
of  the  metal  which  necessitates  a  resort  to  annealing  processes  before  re- 
drawing of  the  shell  may  be  satisfactorily  accomplished. 

In  reference  to  this  allowance  between  the  diameter  of  the  punch  and 
the  inside  wall  of  the  die,  it  has  been  found  desirable,  particularly  with 
first  operation  or  cupping  tools,  to  exceed  the  thickness  of  the  metal  to  be 
drawn  and  allow  from  2J  to  2|  times  the  stock  thickness  between  punch 
and  die  diameters.  A  good  many  shops  working  on  steel  shell  operations 
follow  the  practice  of  making  drawing  dies  with  only  enough  clearance 
between  punch  and  die  for  the  double  thickness  of  material.  In  contrast 
with  this  custom,  some  most  successful  tools  for  cupping  and  several  re- 
drawing operations  have  been  made  for  heavier  work  with  the  drawing  die 
TjV  in.  over  size.  This  gives  a  die  that  works  easily  and  which  is  not 
likely  to  become  quickly  scratched.  The  work  drawn  up  is  more  easily 
ejected  and  where  a  close  degree  of  uniformity  of  wall  thickness  is  not 
essential  the  tools  are  operated  with  entire  satisfaction.  The  material 
naturally  is  not  subjected  to  such  high  stresses  with  the  larger  dies,  and  it 
will  usually  be  found  practicable  to  pass  the  work  through  an  increased 
number  of  operations  before  annealing.  Furthermore  there  is  a  tendency 
for  the  walls  of  the  work  to  thicken  up  under  these  conditions  which  is  a 
feature  of  value  where  increased  strength  is  desired.  And,  the  tools  them- 
selves being  subjected  to  less  severe  service,  are  capable  of  correspondingly 
increased  production. 

THE  DRAWING  EDGE  OF  THE  DIE 

The  drawing  process  starts  with  the  forcing  down  of  the  material  over 
the  edge  of  the  die  and  it  is  at  this  point  that  difficulty  is  likely  to  commence, 
either  with  wrinkling  of  the  work  or  in  fracture  of  the  shell  as  it  is  drawn 
down  through  the  die.  As  stated  in  the  opening  paragraphs,  too  small  a 
radius  at  the  drawing  edge,  too  sharp  a  corner,  puts  the  material  under 
undue  stress  and  may  lead  to  rupture;  although  this  radius  should  be  held 
to  a  low  dimension  when  an  even-ended  shell  is  to  be  produced  in  a  single 
operation.  As  the  radius  of  edge  is  generally  established  for  a  given  ma- 
terial by  the  thickness  of  the  stock,  the  radius  for  thin  material  may  be 
quite  small.  Some  die  makers  recommend  a  rule  for  fixing  the  radius  at 


168 


PUNCHES  AND   DIES 


from  six  to  ten  times  the  thickness  of  the  material,  but  even  this  allows  a 
wide  latitude  for  individual  judgment  and  there  are  numerous  instances 
where  considerable  departure  must  be  made  in  one  direction  or  the  other 
from  the  above  suggestion. 

The  simplest  type  of  blanking  outfit,  one  for  first  operation,  the  pro- 
duction of  a  shallow  cup  from  a  round  disk,  is  represented  by  Fig.  213. 
The  die  in  this  instance  has  a  seat,  or  nest  for  the  reception  of  the  blank 
disk,  and  the  nest  surface  and  die  opening  are  connected  by  the  liberal  round 
,  corner  indicated  so  that 

the  material  will  draw 
down  readily  into  the 
die.  When  the  punch 
has  completed  its  down- 
ward movement  and 
commences  to  rise  the 
shallow  cup  is  stripped 
from  the  end  of  the 
punch  by  the  sharp 
lower  edge  of  the  die 
and  falls  out  of  the 
press. 

This  form  of  die  is 
suited  only  to  the  mak- 
ing of  shallow  draws 
for  it  carries  no  pres- 
sure plate  or  blank 


Cup  Dra\/n 

in  First 

Operation 


FIG.  213.  —  Typical  drawing  die  construction 


holder  to  apply  pressure  to  the  surface  of  the  material  and  so  prevent 
wrinkling  of  the  work  as  it  is  drawn  down  over  the  die  edge.  The  use  of 
the  pressure  plate  is  an  essential  for  general  drawing  operations  as  it  " irons" 
out  the  surface  of  the  work  between  its  face  and  the  opposing  face  of  the 
die  to  eliminate  wrinkles  in  the  metal.  The  degree  of  pressure  applied  to 
the  material  must,  however,  be  regulated  with  judgment,  otherwise  the 
metal  will  be  strained  unduly  in  passing  over  the  radius  of  the  drawing 
edge  of  the  die  and  this  may  lead  to  the  work  breaking  when  passed 
through  subsequent  operations. 

GENERAL  TYPES  OF  DRAWING  DIES 

Besides  the  simple  form  of  die  illustrated  in  Fig.  213  there  are  a  number  of 
types  that  are  used  extensively,  some  of  them  of  a  relatively  complicated 
character.  In  contrast  to  the  non-blanking  dies  just  referred  to,  they  are 
commonly  constructed  to  cut  their  own  blank  and  perform  the  first  drawing 
operation  at  a  single  stroke  of  the  press.  Such  tools  may  be  classed  as 
double  action  cutting  and  drawing  dies  for  use  in  double  action  presses; 


DRAWING  DIES  AND  THEIR  ACTION  UPON   MATERIALS       169 

combination  dies  for  operation  in  single  action  presses;  triple  action  dies 
(which  include  a  further  operation  of  embossing  or  otherwise  working  the 
bottom  of  the  drawn  piece)  which  are  used  in  triple  action  presses. 

Redrawing  dies  of  "push  through"  type  are  quite  similar  to  the  first 
operation  or  cupping  tools,  Fig.  213,  except  that  they  are  adapted  to  receive 
the  formed  cup  instead  of  the  flat  round  blank,  and  to  redraw  the  cup  to 
the  desired  length  and  diameter  by  a  series  of  operations  in  as  many  dies. 

Double  action  dies  are  made  both  of  the  open  or  "push  through" 
type  and  of  solid  bottom  design.  They  each  perform  the  combined  opera- 
tions of  blanking  and  drawing  in  the  one  stroke. 

GENERAL  PRINCIPLES  OF  DOUBLE  ACTION  TOOLS 

These  two  types  of  double  acting  dies  are  illustrated  by  Figs.  214  and 
215  respectively.  The  double  acting  presses  in  which  they  are  used  are 
niade  with  two  slides,  an  outer  slide  which  carries  the  combined  cutting 


FIG.  214.  —  Double  action  cutting  and 
drawing  die:    "Push  through"  type 


FIG.  215.  —  Double  action  cutting  and 
drawing  die:    "Closed  bottom"  type 


punch  and  blank  holder  A  and  which  moves  slightly  in  advance  of  the 
inner  slide  which  carries  the  drawing  punch  B.  The  outer  slide  of  the 
double  action  press  is  so  controlled  that  after  making  its  stroke  downward 
it  stops  during  about  one-quarter  of  the  revolution  of  the  crank  shaft. 

The  blank  disk  having  been  cut  from  the  sheet  by  the  edges  of  punch  A 
and  die  C  drops  into  the  nest  in  the  upper  face  of  die  C  and  is  there  held 
between  the  annular  pressure  surfaces  D  and  E  during  the  down  dwell  of 
the  outer  slide.  While  the  blank  is  thus  held  under  pressure  that  can  be 
regulated  to  suit  the  requirements  of  any  given  case,  the  drawing  punch 
B  continues  its  downward  movement  under  the  action  of  the  inner  slide 


17D 


PUNCHES  AND  DIES 


and  draws  the  metal  from  between  the  pressure  surfaces  D  and  E  into  the 
shape  desired.     In  this  manner  wrinkling  is  prevented. 

For  work  which  is  straight-sided,  cylindrical,  or  prismatic  and  which 
conforms  to  the  shape  of  the  punch  without  requiring  a  counterpart  in 
the  bottom  of  the  lower  die,  tools  of  the  push  through  type,  Fig.  214,  are 
used.  They  admit  of  pushing  the  finished  work  down  through  the  die, 

the  article  being  stripped  from 
the  punch  at  the  beginning  of 
its  up  stroke  by  the  stripping 
edge  F. 

Where  a  counter  pressure 
in  the  lower  die  is  necessary 
the  closed  bottom  type  of  tool, 
Fig.  215,  is  used.  These  dies 
have  in  addition  to  the  lower 
die,  blank  holder,  and  drawing 
punch,  a  push  out  plate  or 
" knock  out"  G  which  is  ar- 
ranged to  rise  at  the  same 
time  as  the  blank  holder  D 
and  thus  lift  the  work  from 
the  die. 

Examination  of  the  view 
of  the  double  acting  press  in 
Fig.  216  will  show  the  method 
of  controlling  the  dies  just  de- 
scribed. This  design  of  press 
makes  use  of  cams  for  actu- 
ating the  outer  slide  H  and 
the  blank  cutter  and  holder, 
while  the  inner  slide  J  with  the  drawing  punch  is  crank  operated.  The 
cams  are  shaped  to  give  any  desired  period  of  dwell  and  the  pressure 
of  the  blank  holder  upon  the  work  may  be  regulated  to  suit  the  re- 
quirements of  the  operation.  Double  action  presses  are  also  made 
with  two  outer  cranks  for  operating  the  outer  slide  with  the  blank  holder. 
Also  they  are  built  with  toggle  action  for  the  operation  of  the  outer  slide, 
these  being  used  more  especially  for  the  larger  and  heavier  drawing  oper- 
ations. 

This  view  of  the  press  also  illustrates  the  arrangement  of  the  knock  out 
apparatus  K  attached  to  the  blank  holder  for  lifting  the  work  from  the 
lower  die  where  solid  bottom  dies,  like  Fig.  215,  are  employed. 


FIG.  216.  —  Double  action  press 


DRAWING  DIES  AND  THEIR  ACTION  UPON  MATERIALS       171 


TRIPLE  ACTION  DIES 

Triple  action  dies  operate  the  same  as  double  action  tools  so  far  as 
concerns  the  blanking,  blank  holding,  and  drawing  operations,  but  as  the 
name  indicates  they  add  a  third  operation  which  may  be  the  embossing, 
stamping,  or  special  forming  of  the  underside  of  the  work,  which  is  accom- 
plished in  the  triple  action  press  by  a  lower  plunger  under  the  bed  which 
rises  to  meet  the  work  as  it  is  drawn  through  the  main  die.  On  the  up 
stroke  the  work  is  stripped  from  the  drawing  punch  by  the  stripping  edge 
under  the  lower  die  and  it  can  then  be  removed  from  the  opening  in  the 
side  of  the  raised  bolster.  A  set  of  dies  of  this  type  with  brief  description 
is  shown  in  connection  with  Fig.  25,  Chapter  I. 

COMBINATION  DIES 

Combination  dies  are  used  extensively  for  such  work  as  cutting  a  blank, 
turning  down  its  edge,  and  forming  it  into  shape  all  at  one  operation.  In 
appearance  and  method  of  operation  such  tools  bear  a  close  resemblance 
to  compound  dies.  They  are  described  at  length  in  Chapter  IX.  Dies  of 
this  class  are  usually  so  arranged  that  the  finished  work  is  ejected  from  the 
die  by  the  action  of  springs,  and  where  an  inclined  press  is  used  the  finished 
article  will  slide  back  out  of  the  machine  by  gravity. 

DIES  FOR  DRAWING  SHELLS 

One  of  the  most  common  uses  for  drawing  dies  is  found  in  the  manu- 
ture  of  cases  for  rifle  cartridges,  and  for  the  various  sizes  of  shells  for  larger 
ammunition.  These  are  of  the  general  type  illustrated  by  Fig.  213,  which 
shows  a  first  operation  set  for  forming  up  a  shallow  cup  which  is  afterward 
extended  to  length  by  a  number  of  drawing  operations. 

The  drawings  that  immediately  follow  represent  in  detail  the  press 
tools  for  producing  1-lb.  cartridge  cases,  dimensions  of  which  are  given 
in  Fig.  217.  The  case  is  of  brass  composed  of  70  per  cent  copper  and  30 
per  cent  zinc.  It  has  an  over-all  length  of  5.389  in.  and  a  diameter  at  the 
mouth  of  1.433  in.,  inside. 

The  shell  is  drawn  up  from  a  cup  made  from  a  disk  of  metal  0.20  in. 
thick  by  2f  in.  in  diameter.  The  disk,  the  cup,  and  the  cupping  tools 
are  all  shown  in  detail  in  Fig.  218.  The  cupping  operation  forms  the  blank 
disk  into  a  shallow  cup  2.084  in.  diameter  by  1  in.  long.  It  will  be  of 
interest  to  note  the  form  of  the  die  for  this  operation.  The  die  body  is  1J 
in.  thick  but  the  drawing  surface,  the  straight  portion  below  the  radius, 
is  only  f  in.  deep.  The  remainder  of  the  depth  is  taken  up  by  the  round 
corner  or  drawing  edge  over  which  the  material  is  worked  as  it  is  pressed 
down  through  the  die. 

The  radius  of  this  corner  is  If  in.  or  eight  times  the  thickness  of  .the 


172 


PUNCHES  AND   DIES 


stock,  so  that  it  falls  well  within  the  rule  recommended  above  for  allowing 
between  six  and  ten  times  the  stock  thickness  for  the  cup  die  radius.  The 
straight  portion  of  the  die,  as  with  the  other  dies  in  the  set,  is  limited  as  noted, 
for  it  is  not  desirable  that  drawing  dies  have  t'oo  long  a  reducing  surface 
as  this  is  likely  to  result  in  the  work  becoming  heated  to  excess  in  passing 
through  the  die,  thus  preventing  proper  lubrication  and  causing  particles  of 


Dimensions  of 
Drawing  Punches 


,         ,  sr — 

1/32        -078  '  |« 57989 1  '-748 

Chamber     Section  of  1-Lb.  Cartridge  Case 

Fig.217 


3rd  Draw     4th  Draw  5th  Draw 

Follow  with  Shell  next 

1  >  Trimming  Trimmed  to 

Of  End  5Ji*  Long 

Fig.222 


can .«« •  -W76 

Header          Tapered  & 
Head  Trimmed 
and  Pierced 


FIGS.  217-222.  —  Tools  for  drawing  1  Ib.  cartridge-cases 

the  material  to  adhere  to  the  die  surface  until  the  accumulation  with  the 
progress  of  the  work  will  bring  about  a  condition  where  the  shells  will  be 
scratched  along  their  length,  if  not  broken  in  the  operation. 

DIE  SHOES  AND  PUNCH  HOLDERS 

The  die  is  held  in  the  shoe  or  bolster,  Fig.  223,  and  the  retainer  plate, 
Fig.  224,  is  used  for  receiving  the  blank  disk  for  cupping.  Both  shoe  and 
retainer  plate  are  shown  with  tables  of  dimensions  to  which  the  openings 
are  bored  to  receive  the  different  dies  and  shells,  for  the  same  pattern  is 
used  for  the  different  sizes  of  parts  entered  therein. 

The  cupping  punch,  Fig.  218,  is  adapted  to  be  carried  in  the  punch 
holder,  Fig.  220,  which  is  bored  to  a  No.  5  Morse  taper,  this  form  of  shank 
being  used  on  all  the  punches  in  the  series. 

The  indenting  die,  Fig.  219,  while  not  a  drawing  device  is  shown  here 
as  a  part  of  the  press  equipment  which  follows  the  cupping  operation  in 
preparing  the  work  for  the  actual  process  of  drawing.  As  indicated  in  the 


DRAWING  DIES  AND  THEIR  ACTION  I}PON   MATERIALS       173 

drawing,  it  forms  up  and  indents  the  base  of  the  shell  to  prepare  a  cavity 
which  is  later  machined  out  to  receive  the  primer.  The  indenting  die  is 
used  in  the  shoe,  Fig.  225. 

Before  this  indenting  operation  is  performed  and  before  each  of  the 
subsequent  drawing  operations,  the  work  is  annealed  and  pickled,  the 
annealing  being  accomplished  in  this  instance  in  a  gas  heated  oven  regu- 
lated by  a  pyrometer  where  the  shells  placed  on  trays  are  submitted  to  an 
average  temperature  of  about  1350°  F.  The  work  remains  in  the  oven  for 
30  minutes  and  is  then  washed  in  pickling  compound  to  remove  the  scale. 

Further  reference  to  annealing  and  pickling  of  such  material  will  be 
made  at  another  point  in  this  chapter. 


Tor  Cupping  and  Drawing  Dies 
Fi«.223 


f Round-SW-12-Dia-  - 

For  Indenting  Die 

Fig.225 


Die  Shoe  or  Bolster 

Heading  Dies 

Fig.227 


FIGS.  223-228.  —  Tools  for  drawing  1  Ib.  cartridge  cases 

THE  DRAWING  TOOLS 

There  are  five  drawing  operations  which  follow  the  indenting  of  the 
shell,  and  the  details  of  punches  and  dies  for  the  work  are  given  in  Fig.  221, 
where  the  table  at  the  side  of  the  punch  and  die  layout  gives  the  important 
dimensions  of  the  various  tools  in  the  series.  The  drawing,  Fig.  222,  shows 
the  shell  in  its  different  stages  as  it  progresses  toward  completion.  The 
punches  are  carried  in  holders,  like  Fig.  220,  the  dies  in  shoes  or  bolsters 
like  Fig.  223.  From  the  second  drawing  on,  the  spring  stripper,  Fig.  226, 
is  used. 

Following  the  fourth  drawing  operation  the  end  of  the  shell  is  trimmed 
and  after  the  fifth  draw  it  is  trimmed  again  to  length.  Then  it  is  headed 
by  the  tools  shown  in  Fig.  227,  the  open  end  is  annealed  and  the  taper 
formed  by  the  dies,  Fig.  228. 


174  PUNCHES  AND  DIES 

The  operations  of  finishing  the  flange  or  head,  the  machining  to  length, 
the  forming  of  the  primer  hole  and  recess  are  not  performed  in  press  tools 
and  need  not  be  described  here.  It  is  believed  however  that  it  will  be  of 
value  for  purposes  of  reference  to  include  here  the  complete  schedule  of 
operations  in  this  shell  manufacture  and  the  accompanying  table  is 
accordingly  reproduced.  The  items  marked  with  an  asterisk  are  press 
operati  ons. 

SCHEDULE  OF  OPERATIONS  ON  SHELLS 

1.  *  Blank. 

2.  *  Cup.     Punch  and  Die,  Fig.  218;  Punch  Holder,  Fig.  220;  Bolster,  Fig.  223; 
Retainer  Plate,  Fig.  224. 

3.  Anneal  and  Pickle. 

4.  *  Indent.    Punch  and  Die,  Fig.  219;  Punch  Holder,  Fig.  220;  Bolster,  Fig.  225; 
Retainer  Plate,  Fig.  224. 

5.  Anneal  and  Pickle. 

6.  *  First  Draw.     Punch  and  Die,  Fig.  221;  Punch  Holder,  Fig.  220;  Bolster,  Fig. 
223;  Retainer  Plate,  Fig.  224. 

7.  Anneal  and  Pickle. 

8.  *  Second  Draw.     Punch  and  Die,  Fig.  221;  Punch  Holder,  Fig.  220;  Bolster, 
Fig.  223;  Retainer  Plate,  Fig.  224;  Stripper,  Fig.  226. 

9.  Anneal  and  Pickle. 

10.  *  Third  Draw.     Punch  and  Die,  Fig.  221;  Punch  Holder,  Fig.  220;  Bolster, 
Fig.  223;  Retainer  Plate,  Fig.  224;  Stripper,  Fig.  226. 

11.  Anneal  and  Pickle. 

12.  *  Fourth  Draw.     Punch  and  Die,  Fig.  221;  Punch  Holder,  Fig.  220;  Bolster, 
Fig.  223;  Retainer  Plate,  Fig.  224;  Stripper,  Fig.  226. 

13.  Trim  to  Length. 

14.  Anneal  and  Pickle. 

15.  *  Fifth  Draw.  Punch  and  Die,  Fig.  221;  Punch  Holder,  Fig.  220;  Bolster,  Fig. 
223;  Retainer  Plate,  Fig.  224;  Stripper,  Fig.  226. 

16.  Trim  to  Length. 

17.  *  Head.     All  Tools  in  Fig.  227. 

18.  Anneal  Open  End  and  Wash. 

19.  *  Form  Taper.     All  Tools  in  Fig.  228. 

20.  Face  and  Finish  Machine.     Flange  and  Rough  Out  Primer  Hole. 

21.  Machine  to  Length. 

22.  Burr  Inside  of  Primer  Hole. 

23.  Finish-Machine  Primer  Hole  and  Form  Recess. 

24.  Wash. 

25.  Final  Inspection. 

26.  Stamp. 

27.  Pack  for  Shipment. 

THE  FORM  OF  THE  DRAWING  DIES 

It  will  be  noticed  that  all  of  the  drawing  dies  for  this  case  are  made  as 
in  Fig.  221  with  T%  in.  depth  of  drawing  or  reducing  surface  and  the  portion 
immediately  above  is  bell  mouthed  out  to  an  angle  of  15  degrees  on  a  side 
from  the  vertical.  The  corners  are,  of  course,  lapped  off  to  dispose  of  the 


le 


The  Dlank 


I  I 

=$, 


Wfm V%M%7/. 

|<- — 4 .463*4  -  -^gggfe  u°Jt  ^ 

Ounnincr  Di«  'l 


Cup  Produced 

4.463'o.S.Dia. 

2.12&Long 


k 4.204- H 

j-4.248— 

,     1st  Drawing  Die 


4th  Drawing  Die 


Drawing  Punch 
Drawing  Punch  Dimensions 


4     lat 
A  Draw 

2nd 
Draw 

3rd 
Draw 

4th 
Draw 

5th 
Draw 

6th 
Draw 

A  M 

10 

12 

12X 

17H 

20^ 

B  3.323 

3.760 

3.770 

3.040 

3.GOO 

3.500 

C     K 

M 

1.055 

0.975 

0.812 

0.820 

D 

3.738 

3.773 

3.712 

3.685 

E 

8 

IOH 

10 

10.42 

F  3.838 

3.320 

3.778 

3.723 

3.712 

3.094 

G=A 

=A 

=A 

=A 

=  A 

=  A 

H   5% 

6% 

7« 

10 

\2H 

20% 

J  — 





— 

3.827 



K  — 

— 





.75 



R    .5 

.5 

1.2 

.75 

— 

.50 

S  — 

~ 

1.08 

1.08 

1.08 

1.03 

7.148— - 
Gth  Drawing  Die 

Slight  Bound -at  Corners 


f  2nd  Trim  After  \ 
V.        Gth  Draw      ) 


1 


0.18 


SECTION  OF  CASE 


11 


--11.58 


FIG.  229.  —  Drawing  dies  for  18  Ib.  cartridge  cases 


PAGE  175 


176 


PUNCHES  AND   DIES 


sharp  edge  at  the  drawing  point  and  it  is  also  important  that  the  working 
surfaces  of  die  and  punch  be  very  hard  and  smooth  to  avoid  possibility  of 
rapid  wear  and  defacing  of  the  surface  of  the  work. 

The  question  of  reduction  in  successive  drawing  operations,  or  the 
percentage  of  total  reduction  to  be  accomplished  by  each  set  of  dies  is  of 
importance  and  a  number  of  illustrations  are  here  given,  showing  dimensions 
of  other  drawing  dies  operating  on  similar  products.  From  these  can  be 
gathered  the  successive  steps  in  producing  the  completely  drawn  shell, 
as  well  as  the  details  of  the  form  of  the  interior  of  the  die. 

Thus  Fig.  229  shows  a  set  of  drawing  dies  for  an  18-lb.  cartridge  case, 
the  series  of  sections  included  in  the  drawing  starting  with  the  cupping  die 
and  covering  the  six  drawing  dies  in  the  series.  The  notation  at  the  side 


Size  of  Blank    5%   Dia.  x  .380  Thick 


Angle      20  for  First  Drawing  Die) 


Dia.=D  for  the  Fi 

ve  Drawing  Dies 

1st  Draw 

2nd  Draw 

3rd 

Draw 

4th  Draw 

5th  Draw 

5.020" 

4.898" 

4. 

soo" 

4.725" 

4.718/r 

FIG.  230.  —  Drawing  dies  for  4.5  Howitzer  cases 

of  the  sketches  gives  the  outside  dimensions  of  the  shell  as  it  progresses 
from  cup  to  final  drawing,  and  the  table  gives  the  dimensions  of  the  cor- 
responding  series  of  drawing  punches.  The  latter  will  be  seen  to  be 
tapered  back  from  the  end  by  an  amount  averaging  about  0.010  in.  per  in.  of 
length  and  various  sets  of  tools  measured  for  different  work  of  similar 
nature  are  tapered  in  about  the  same  proportion,  though  this  taper  is  apt 
to  run,  as  a  rule,  somewhat  less  to  the.  inch  for  the  longer  draws  and  the 
final  punch  and  correspondingly  more  for  the  first  punches.  For  example, 
in  the  case  of  one  set  of  tools  for  practically  the  same  size  of  shell,  the  taper 
ranges  from  0.020  per  in.  for  the  first  drawing  punch  to  0.010  in.  for  the  sixth 
or  final  drawing  punch.  These  figures  apply  to  the  working  portions  of 
the  punches,  the  total  length  of  which  measured  under  the  shoulder  is 
considerably  greater  than  the  actual  depth  of  the  shell  drawn. 

The  sketch  and  table,  Fig.  230,  give  the  dimensions  of  the  cupping  and 


DRAWING   DIES  AND  THEIR  ACTION  UPON  MATERIALS       177 


drawing  dies  for  a  4.5  howitzer  cartridge  case  which  is  a  comparatively 
short  shell  but  which  is  nevertheless  passed  through  five  drawing  dies  after 
the  cupping  of  the  blank  is  accomplished.  These  dies  have  a  working 
surface  somewhat  deeper  than  usual  but  the  draw  at  each  operation  is  very 
short  as  compared  with  the  (  n  „ 

majority  of  work  of  the  same 
character. 


The  Cup 


21 

1st  Draw     I 


Approximate 
Dia             Length 

la  Draw 

21/32 

34" 

•2ud  Draw 

5/s" 

iV 

3rd  Draw 

Vw 

m" 

4th  Draw 

H" 

2l/&"    ' 

5th  Draw 

15/32' 

2  l*/w 

T7T1 


i 


i 


i. 


5th  Draw 
(  Last  Draw) 


Finished 
Case 


SMALLER   WORK 

In  drawing  smaller  cases 
—  as  for  0.30  caliber  rifle 
cartridges,  a  blank  is  used 
which  is  1TV  in.  diameter  by 
0.808  in.  thick.  This  is 
formed  into  a  cup  f  in.  diam- 

eterbyj  in.  long  and  the  first  FJG  231._Drawingoperatio;;";";3o"clrtridge7ases 
drawing  operation  produces  a 

shell  §£  in.  diameter  by  J  in.  long.  The  sketch,  Fig.  231,  shows  the  suc- 
cessive stages  of  drawing.  As  with  the  larger  cases,  these  shells  are  an- 
nealed before  each  of  the  drawing  operations. 

A  design  of  blanking  and  cupping  die,  recommended  by  an  authority 

for  this  class  of  work,  is  shown  in 
Fig.  232.  Here  A  is  the  die  which 
is  made  with  as  large  a  cupping 
radius  as  possible  to  allow  the  shell 
to  draw  easily.  The  bottom  of  the 
die  is  relieved  and  the  square  edge 
A  forms  a  good  stripper  which  is 
positive  in  its  action  as  the  shell 
will  expand  enough  after  it  has  been 
drawn  through  the  die  to  prevent 
it  from  going  back  up  through  the 
die  when  the  punch  returns.  This 
die  is  secured  in  a  holder  B  by  re- 
taining ring  C,  which  is  threaded 
and  screwed  into  the  holder. 


FIG.  232.  —  Blanking  and  cupping  tools  for 
rifle  cartridge  cases 


The  part  D  is  a  stripper  of  the  ordinary  type  for  the  blanking  die  and 
punch  E  which  is  secured  in  the  drop  forged  holder  F,  a  detail  of  which  is 
shown  to  the  right.  The  drawing  punch  G  has  a  vent  hole  the  same  as  the 
other  punches  illustrated,  to  prevent  trouble  with  the  shells  sticking  to 
the  ends  of  the  punch  because  of  the  vacuum  held  by  the  fit  of  the  work 
to  the  punch  surface.  It  will  be  noticed  that  the  top  of  the  punch  is  slotted 
crosswise  on  opposite  sides  to  receive  the  jaws  of  a  holder  H  on  the  press 


178 


PUNCHES  AND   DIES 


slide.  This  provides  a  floating  connection,  as  the  holders  may  be  clamped 
in  position  and  the  holes  for  F  and  H  tapped  in  their  respective  punch 
holder  plates.  The  floating  drawing  punch  holder  is  shown  in  detail  H 
at  the  right  in  Fig.  232. 

On  work  of  this  class  it  is  customary  to  operate  the  blanking  and  cup- 
ping tools  on  the  multiple  principle  with  either  two  or  four  sets  of  dies  in 
the  double  acting  press. 

PROPER  VENT  IN  PUNCH  NECESSARY 

Reference  may  again  be  made  here  to  the  necessity  of  properly  venting 
the  drawing  punch  on  work  of  this  character.  Besides  the  trouble  likely 
to  be  caused  by  the  shell  sticking  to  the  punch  when  the  air  cannot  escape, 
there  is  occasionally  difficulty  brought  about  by  insufficient  passage  room 
for  the  lubricating  liquid.  An  instance  of  this  kind  recently  brought  to 

attention  in  a  shop 
handling  various 
classes  of  shell  draw- 
ing operations  is  illus- 
trated by  Fig.  233. 
This  is  an  explanation 
of  some  of  the  so- 
called  " freak"  shells 
that  are  now  and  then 
produced : 

In  the  engraving,  views  A  and  B  show  a  certain  kind  of  shell  as  it  should 
be  drawn  and  C  represents  a  freak  form  discovered  sometimes  in  putting 
through  a  lot  of  these  shells.  This  was  caused  during  the  redrawing  of 
the  large  diameter  by  an  unusual  amount  of  soap  water  used  as  a  lubri- 
cant and  occasionally  left  in  the  bottom  of  the  shell.  As  the  solution  could 
not  escape  through  the  air  hole  in  the  ram  when  the  punch  descended,  the 
result  was  that  the  solution  ahead  of  the  punch  acted  upon  the  shell  in  the 
manner  indicated  at  D.  This  in  turn  caused  the  bulged  part  of  the  shell 
to  be  forced  through  the  redrawing  die  without  being  operated  on  by  the 
punch,  which,  in  turn,  caused  this  part  of  the  shell  to  bulge  after  it  was 
forced  through  the  working  part  or  edge  of  the  die. 

This  trouble  was  remedied  by  drilling  a  larger  air  hole  in  the  punch  to 
allow  the  water  to  escape,  and  using  care  to  keep  the  lubricant  out  of  the 
shells  as  far  as  possible  preparatory  to  feeding  them  to  the  die. 

ONE  METHOD  OF  CUPPING  THICK  METAL 

Double  acting  presses  and  combination  dies  are  not  always  available 
or  practicable  for  certain  work  that  comes  along  and  when  it  is  necessary 
to  draw  a  shell  from  thick  stock  without  such  facilities  a  safe  and  efficient 


FIG.  233.  —  A  freak  shell  and  how  it  was  made 


DRAWING  DIES  AND  THEIR  ACTION  UPON  MATERIALS       179 


method  is  to  blank  the  piece  first  and  then  cup  it  by  means  of  tools 
similar  to  those  shown  in  Fig.  234.  Here  the  drawing  die  is  shown  at  C, 
the  punch  at  D,  the  bolster  at  E,  and  the  stripper  at  F. 

The  blank  is  inserted  into  the  nest  G  as  provided,  after  which  the 
stripper  F  is  screwed  down  onto  the  blank  to  create  pressure  much  the 
same  as  when  a  double  acting  press  is  used.  This  method  has  given  per- 
fectly satisfactory  results,  although,  of  course,  it  is  necessarily  slow  as 
compared  with  the  operation  of  similar  work  in  the  usual  equipment. 


FIG.  234.  —  Clamp  plate  on  die 


Cupping  Die 
\sj  Operation 

FIG.  235 


A  COMPARISON  OF  DIE  EDGES 

Too  much  emphasis  cannot  be  placed  upon  the  importance  of  properly 
shaped  die  edges,  and  although  reference  has  already  been  made  to  this 
point,  it  may  be  well  to  present  here  a  comparison  of  proper  and  im- 
proper drawing  edges. 

Thus  in  Fig.  235  a  sectional  view  of  a  cupping  die  is  given,  showing  a 
liberal  radius  at  A  while  an  improper  sharp  corner  is  seen  at  B.  As  noted 


FIG.  236.  —  Shell  drawing  dies 

in  preceding  pages,  such  a  corner  would  result  in  causing  undue  stress  in 
the  material  and  if  the  tensile  strength  of  the  stock  were  exceeded  the  shell 
would  be  ruptured  or  fractured.  < 

Referring  to  Fig.  236,  all  sharpness  of  the  edges  at  the  drawing  point  in 
a  drawing  die  should  be  avoided  and  too  abrupt  angles  or  leads  should  not 
be  permitted.  Thus  the  slope  of  the  angle  in  the  mouth  of  drawing  die  C 
is  shown  with  nicely  rounded  corner  to  allow  the  metal  to  draw  or  flow 
properly.  However,  after  the  die  has  been  in  service  for  some  time  it 
may  be  noticed  that  the  shell  has  become  shorter,  owing  to  the  wearing 
down  or  undercutting  of  this  edge  as  indicated  at  D. 


180  PUNCHES  AND   DIES 

ANNEALING  AND  PICKLING  OF  BRASS  SHELLS 

In  this  section  relating  to  the  drawing  of  brass  shells  it  may  be  well  to 
include  a  few  notes  in  reference  to  the  annealing  and  pickling  operations 
which  are  generally  so  essential  between  the  successive  draws  for  the  pro- 
duction of  satisfactory  work  and  the  preservation  of  the  drawing  tools. 

While  annealing  is  sometimes  eliminated  preparatory  to  a  reduction,  it 
is  not  advisable  usually,  for  the  material  then  becomes  too  hard  and  brittle, 
particularly  when  thin  stock  is  drawn.  The  work  is  then  severe  upon  the 
dies  and  in  cases,  like  the  redrawing  of  shells,  say,  f^  diameter  by  4  in. 
long,  of  O'.OlO-in.  stock,  it  has  been  noticed  that  the  product  is  inclined  to 
be  crooked  or  bent  when  not  previously  annealed.  Another  condition 
that  will  result  in  bent  shells  is  having  the  back  of  the  die  broken  out;  this 
naturally  does  not  occur  when  the  diameter  of  the  shell  is  large  or  it  is 
drawn  from  thick  stock. 

Pitting  of  the  die,  scratched  work,  and  shell  breakage  are  largely 
attributed  to  lack  of  sufficient  precaution  in  this  direction.  Too  little 
annealing  is  as  detrimental  as  its  extreme,  and  should  the  annealing  be 
insufficient  (1000  to  1100  F.  is  usually  about  correct),  the  bottom  of  the 
shell  is  likely  to  punch  out;  the  die  will  pit  very  easily.  On  the  other 
hand,  work  that  has  been  subjected  to  too  high  a  temperature  has  de- 
creased ductility  and  tensile  strength.  Under  this  latter  condition  a 
shell  may  or  may  not  draw  to  its  full  length,  although  should  ho  breakage 
occur,  the  smooth  finish  that  is  most  desirable  is  lacking,  and  in  its  place 
appears  an  uneven,  scaly  product. 

CARE  NECESSARY  IN  ANNEALING 

Extreme  care  should  be  used  in  annealing.  If  a  pyrometer  is  not  avail- 
able, adjust  the  furnace  until  it  shows  a  bright  red  glow,  allowing  the  work 
to  remain  therein  a  sufficient  length  of  time  to  bring  all  pieces  to  a  like  color, 
say,  a  cherry  red. 

If  the  temperature  of  the  furnace  is  not  increased,  the  work  will  not 
become  overheated,  even  though  the  shells  are  allowed  to  remain  in  it 
longer  than  the  predetermined  time.  Use  sheet  iron  pans  with  covers, 
to  prevent  oxidation  of  the  work  and  lessen  the  labor  of  pickling,  but  see 
that  the  shells  are  free  from  soap  or  oil  and  that  they  are  washed  thoroughly 
before  the  annealing  operation.  After  the  annealing  the  work  is  pickled 
in  order  to  remove  all  evidence  of  scale  or  oxidation,  and  it  should  be  re- 
membered that  the  same  degree  of  caution  is  required  as  for  the  annealing 

process. 

THE  PICKLE  BATH 

For  the  pickle,  ten  parts  of  water  to  one  of  sulphuric  acid  gives  a  satis- 
factory mixture  for  warm  pickle;  but  if  cold,  seven  parts  of  water  to  one 
of  sulphuric  acid  is  a  good  combination.  This,  however,  may  be  mixed  to 

I 


DRAWING  DIES  AND  THEIR  ACTION  UPON   MATERIALS       181 

suit  conditions.     In  preparing  the  bath  always  put  the  water  in  first,  the 
acid  last,  the  chemical  action  making  this  precaution  necessary. 

After  all  oxidation  is  removed,  the  shells  should  be  immersed  and 
washed  thoroughly  in  hot  or  boiling  water.  Lukewarm  water  will  not 
suffice.  The  equipment  for  this  should  consist  of  a  wooden  tank  with  pro- 
vision for  an  outlet  and  an  inlet  for  a  continuous  supply  of  clear  water. 
Should  this  operation  be  improperly  performed  and  the  work  be  exposed  to 
the  air,  it  will  be  noticed  that  reddish  spots  appear  upon  the  surface  of  the 
shells,  and  in  some  instances  a  green  sediment  or  verdigris,  which  is  nothing 
but  the  acid,  a  condition  to  be  particularly  avoided.  The  shells  on  top 
may  not  appear  to  be  as  mentioned,  but  investigation  of  the  work  halfway 
down  or  at  the  bottom  will  surely  result  in  this  finding. 

EFFECT  OF  THE  ACID  ON  THE  TOOLS 

It  is  needless  to  state  that  the  acid  has  quite  an  affinity  for  steel;  and 
should  the  work  in  the  condition  mentioned  be  redrawn,  not  much  progress 
will  be  made  as  the  tools  will  become  pitted  almost  immediately  and  eventu- 
ally ruined. 

Suppose  acid  spots  have  not  made  their  appearance;  this  does  not 
necessarily  mean  that  the  work  is  clean.  Shells  are  improperly  cleaned 
so  long  as  there  is  a  vestige  of  scale  or  oxidation  upon  them,  and  it  is  then 
time  to  strengthen  the  mixture  or  to  investigate  the  methods  of  the  work- 
man, who  perhaps  has  passed  the  shells  in  too  great  a  hurry. 

The  redrawing  of  shells  that  have  any  oxidation  upon  them  is  simply 
impracticable  and  profitless.  Aside  from  the  wear  caused  on  the  tools, 
difficulty  will  be  encountered  in  the  plating  or  finishing  department  with  the 
bright  dipping  or  plating  as  the  case  may  be,  all  because  the  scale  has  been 
ironed  into  the  surface  of  the  shell  by  the  drawing  process. 

A  good  way  to  prevent  the  oxygen  from  acting  upon  the  shells  is  to 
immerse  them  in  a  receptacle  of  some  kind  filled  with  water  or  a  soap  mix- 
ture. Attached  to  it  should  be  a  pipe  for  heating.  If  there  is  any  acid  on 
the  shells  it  will  soon  rise  to  the  surface  in  a  curdled  state,  where  it  is  very 
readily  skimmed  off. 

Redrawing  tools  should  always  be  kept  in  a  perfectly  smooth,  brightly 
polished  condition  so  far  as  possible  to  assure  satisfactory  operation;  but 
if  conditions  exist  such  as  noted  above  even  this  care  of  the  punches  and 
dies  will  be  of  little  avail. 

EXPERIENCE  WITH  STEEL  SHELLS 

There  is  some  difference  of  opinion  in  respect  to  the*relative  difficulties 
of  drawing  brass  and  steel  shells,  particularly  in  reference  to  the  annealing 
operations  required.  It  has  been  the  observation  of  some  that  in  cupping 
and  deep  drawing  of  sheet  metal,  steel  can  be  drawn  deeper  than  brass 


182 


PUNCHES  AND   DIES 


without  annealing  although  the  first  draw  on  a  brass  shell  can  be  made 
slightly  deeper  than  steel.  It  is  necessary  to  run  the  press  a  little  slower 
for  steel  than  for  brass. 

In  Fig.  237, 'at  A  and  B,  are  shown  some  steel  shells  which  were  made  in 
one  operation.  Those  at  C  and  D  require  two  draws  although  at  times 
material  has  been  available  from  which  tkese  could  be  drawn  in  one  oper- 
ation. The  largest  of  these  shells  have  always  been  made  in  two  draws, 
and  the  same  shop  is  now  using  two  draws  on  all  shells  that  have  a  length 
equal  to  the  diameter.  After  trimming,  the  large  shells  are  threaded  but 
there  is  no  annealing  between  operations.  It  is  believed  that  if  the  shells 
were  of  brass  it  would  be  necessary  to  anneal  them  after  the  first  operation. 


FIG.  237.  —  Steel  shells  drawn  without  annealing 

At  Ej  F,  and  G  are  shown  the  three  operations  necessary  to  make  the 
piece  from  0.018-in.  cold  rolled  steel.  There  are  two  draws  followed  by 
rolling  of  the  thread  but  no  annealing  is  done  between  operations. 

From  H  to  K  are  shown  the  successive  steps  in  making  a  screw  drivei 
ferrule  of  0.030-in.  cold  rolled  steel.  This  is  also  made  without  annealing, 
but  if  it  were  of  brass  it  would  be  necessary  to  anneal  it  at  least  once. 

Two  METHODS  OF  DRAWING  A  DEEP  FLANGED  STEEL  SHELL 

Individuality  of  experience  and  method  is  nowhere  more  pronounced 
than  among  expert  mechanics  responsible  for  the  production  and  operation 
of  press  tools.  There  are  usually  several  ways  to  solve  a  given  problem 
in  die  construction,  and  the  character  of  the  tool  layout  for  a  difficult  piece 
of  work  will  differ  in  accordance  with  the  experience  of  the  men  who  have 
the  matter  in  hand. 

One  method  of  attacking  the  problem  represented  by  Fig.  238  is  as 
follows:  The  flanged  shell  here  shown  is  made  in  seven  operations,  one 
blanking,  four  drawing,  one  trimming,  and  a  final  forming  operation  to 
turn  up  the  edge  on  the  flange.  The  material  is  0.035-in.  drawing  steel 


DRAWING  DIES  AND  THEIR  ACTION  UPON   MATERIALS       183 


and  the  shell  is  finished  without  any  annealing.  The  blanks  are  made  on  a 
rotary  shearing  machine.  They  are  then  run  through  an  ordinary  "push 
through"  type  of  drawing  die,  making  a  straight  shell  5.75  in.  diameter,  3 
in.  long.  '  .  . 

For  the  second  operation  the  same  type  of  die  is  used  but  it  has  an  in- 
side blank  holder  to  prevent  the  stock  from  wrinkling;    and  instead  of 


-10.100- 


No.lDrem 
NaEDrem* 


5.75-— 


NaSDrcm 


No.  4  Draw 


Form  Flange 


f* 


\ 

K-- 


-5.000 — 


—4250'- > 


- SSOCf- - 


: 5.6875"- > 


\ 


<—  _i 


FIG.  238.  —  Drawing  a  flanged  shell 

pushing  the  shell  through,  it  is  draw,n  just  far  enough  to  leave  a  flange 
the  size  of  the  radius  on  the  drawing  edge  of  the  die.  This  is  the  starting 
of  the  flange.  The  trimming  operation  follows  in  ord3r  to  make  the 
flange  round.  This  was  found  necessary  in  order  to  obtain  the  required 
uniformity  of  pressure  in  the  next  drawing  operation.  The  trimming  is 
done  with  press  tools,  the  punch  being  the  lower  member  and  the  die  the 
upper.  The  piece  is  located  centrally  on  the  pu:ich  by  means  of  a  pilot  the 
size  of  the  inside  diameter  of  the  shell. 

The  third  drawing  operation  reduces  the  shell  from  5  in.  to  4.250  in. 
in  diameter.  The  die  is  of  the  same  form  except  that  it  has  a  cast  iron 
stripper  plate  to  the  underside  of  which  is  fastened  a  tool  steel  ring  that 
acts  as  a  pressure  plate.  When  the  descending  punch  comes  in  contact 
with  the  stripper,  it  flattens  out  the  flange  on  the  face  of  the  die  as  the 
punch  completes  the  down  stroke.  The  radius  joining  the  flange  and  the 
body  of  the  shell  is  now  finish  size.  It  required  some  experimenting  to  de- 
termine the  correct  time  for  the  pressure  plate  to  come  into  contact  with 
the  flange  as  the  shell  was  being  drawn,  in  order  to  exert  enough  pressure 
on  the  flange  to  keep  it  from  wrinkling,  yet  not  enough  to  cause  it  to  roll 
over. 


184 


PUNCHES  AND  DIES 


THE  FOURTH  DRAW 

The  fourth  drawing  operation  reduces  the  shell  from  4.259  to  3.6875 
in.  in  diameter.  In  this  draw  it  seems  to  require  sufficient  pressure  to 
cause  the  flange  to  roll  in  order  to  prevent  it  from  developing  wrinkles. 
Then  as  the  flange  is  flattened  at  the  bottom  of  the  stroke  there  is  a 
circular  crease  on  the  flange  due  to  the  action  of  the  metal  in  being  bent 

beyond  a  horizontal  plane 
and  straightened  out  again. 
Owing  to  the  flange  not 
being  strong  enough  to 
stand  the  stress  of  strip- 
ping, it  has  been  found 
impracticable  under  exist- 
ing circumstances  to  turn 
up  the  edge  on  the  flange 
in  the  finish  operation.  It 
is  therefore  necessary  to 
make  a  separate  operation 
of  this,  the  final  one  in  the 
development  of  the  piece. 

Referring  to  Fig.  239,  A 
is  a  cast  iron  punch  holder 
bolted  to  the  ram  of  a 
toggle  press  with  13  in. 


stroke;  B  is  a  jacking  ring 
and  C  the  punch.  At  D 
is  the  stripper  plate  and  E 
is  a  tool  steel  pressure  plate, 
the  radius  on  which  is  made 
to  conform,  to  that  on  the 
dies  so  as  to  iron  out  the 
metal  on  the  flange.  A  posi- 
tive knock  out  T  is  operated 
by  side  rods  screwed  into 


FIG.  239.  —  Arrangement  of  the  dies  for  drawing 
shells  shown  in  Fig.  238 


the  ram  of  the  press.  At  G  is  the  die  and  at  H  the  die  shoe,  which  is  bolted 
to  the  bed  of  the  press.  The  duty  of  the  two  springs  U  is  to  keep  the 
stripper  D  up  on  the  punch  and  out  of  the  way  of  the  operator.  The  two 
rods  S  on  the  side  serve  as  guide  rods.  They  also  hold  the  stripper  plate  D 
in  place  as  the  punch  ascends,  thus  pulling  the  shell  from  the  punch. 

By  trying  out  various  diameters  for  the  punches,  it  was  found  that 
best  results  were  obtained  when  the  diameter  of  the  punch  was  from  0.010 
to  0.012  in.  smaller  than  the  size  determined  by  subtracting  the  double 


DRAWING  DIES  AND  THEIR  ACTION  UPON   MATERIALS       185 


thickness  of  the  stock  from  the  inside  diameter  of  the  die.  The  lubricant 
used  was  a  compound  to  which  was  added  about  20  per  cent  of  lard  oil 
and  a  small  quantity  of  sulphur. 

AN  ALTERNATIVE  METHOD 

Another  method  which  has  been  suggested  for  handling  this  shell  draw- 
ing undertaking  is  as  follows;  it  being  believed  that  the  shell  could  be 
blanked  and  drawn  in  three,  possibly  two  operations.  This  method  refers 
to  dies  for  a  double  acting  press,  and  Fig.  240  shows  the  type  of  die  used 
for  blanking  and  cupping.  The  blanking  punch  acts  as  a  flange  holder 
for  holding  the  stock  when  drawing.  The  head  on  the  drawing  pad  or 
die  irons  out  all  wrinkles  that  tend  to  form  in  the  stock.  The  cup  does 
not  have  to  be  drawn 

2B2 


entirely  through  the 
die,  but  can  be  left 
with  a  flange  and  can 
be  about  the  size  of 
the  second  draw  in 
Fig.  238. 

The   blanking  die 

must    have   shear 

,          ,,          ,   ,,  FIG.  240  FIG.  241 

ground  on  it,  and  trie 

i     i  FIGS.  240-241.  —  Drawing  steel  shells 

pressure    exerted    by 

the  flange  holder  must  be  regulated  to  keep  out  all  wrinkles  and  not 
thin  the  stock  down  too  much.  The  head  must  have  a  large  radius,  so 
that  the  stock  will  not  be  broken  and  pulled  in.  About  f  or  f  in.  is  recom- 
mended for  the  size  cup  here  shown.  The  drawing  punch  must  be  regu- 
lated to  draw  the  right  depth.  These  points  can  be  determined  by 
trial. 

The  type  of  die  used  for  the  drawing  operations  is  shown  by  Fig.  241. 
This  is  also  a  double  acting  die.  The  die  block  is  belled  out  to  take  the 
cup  from  the  preceding  die  and  has  a  large  radius  ori  the  edge  of  the  draw- 
ing portion  of  the  die.  A  flange  holder  comss  down  inside  the  shell  and 
holds  the  stock  so  no  wrinkles  can  form,  while  the  ram  draws  the  cup  as 
before  to  the  proper  depth. 

After  the  shell  has  been  reduced  to  the  proper  diameter,  the  flange 
should  be  flattened  out  on  a  single  acting  press  and  then  trimmed.  All 
dies  should  have  guide  studs  or  posts  to  aid  in  setting  up  and  keeping  them 
in  line.  If  one  stud  is  made  larger  than  the  other,  the  die  and  punch  will 
not  turn  in  relation  to  each  other  but  will  go  together  the  same  way  each 
time. 


186 


PUNCHES  AND   DIES 


THE  " PINCH  OFF"  TYPE  OF  PUNCH  AND  DIE 

The  principle  of  the  draw  and  " pinch  off"  punch  and  die  is  used 
extensively  in  making  jewelry  settings  and  similar  parts  but  is  little  known 
outside  of  factories  specializing  on  this  line  of  operations.  The  following 
description  relates  to  a  punch  and  die  of  this  kind  for  making  the  box  cover 
shown  in  Fig.  242.  The  stock  is  0.014-in.  low  brass,  dead  soft,  and  the 
press  is  a  single  action  machine  run  at  150  revolutions  per  minute. 

The  tools  are  shown  in  Fig.  243.  The  one  feature  to  be  emphasized  is 
the  fact  that  with  these  tools  properly  made,  and  regardless  of  a  slight 
variation  in  the  thickness  of  the  stock,  the  cups  or  shells  will  always  be  of 
uniform  height  if  the  trimming  punch  is  kept  sharp.  In  the  engraving,  A 
is  the  die;  B  is  the  stripper  which  is  held  in  place  by  cap  screws  C.  It  will 

be  noticed  that  the  draw- 
ing edge  D  of  the  die  is 
well  rounded.  The  exact 
amount  for  this  work  can 
be  determined  only  by  trial, 
although  a  man  accustomed 
to  these  dies  can  almost  al- 
ways get  the  radius  right 
at  the  first  attempt.  There 
is  one  important  thing  about 
this  radius,  that  is  it  should 
not  run  into  the  straight 
part  of  the  die  A  at  a  tan- 
gent but  should  run  out  as  shown  in  the  section  at  K,  leaving  an  abrupt 
shoulder,  as  at  L.  This  assists  the  pinch  off  punch  to  trim  the  cup  evenly. 
In  making  dies  for  shallow  settings  it  is  only  necessary  to  break  the  edge 
with  an  oil  stone.  Another  important  point  is  that  the  die  should  be 
ground  absolutely  parallel  without  any  clearance  and  the  stripping  edge 
E  of  the  die  must  be  sharp  in  order  to  strip  the  cup  from  the  drawing 
punch  F. 

The  pinch  off  punch  G  is  left  large  for  grinding,  and  is  drilled  and 
tapped  for  a  standard  thread.  The  end  of  the  punch  is  bored  as  shown. 
This  is  to  permit  regrinding  on  the  face  to  sharpen  and  also  to  act  as  a 
means  of  keeping  the  drawing  punch  F  concentric  with  the  blanking  punch. 
This  latter  feature  is  not  usual  in  the  practice  of  jewelry  tool  makers,  who 
generally  make  the  punch  in  one  piece.  In  this  case  it  is  necessary  when 
resharpening,  to  anneal  the  punch,  true  it  up  carefully  in  the  lathe,  turn 
back  the  pinch  off  shoulder  as  well  as  the  draw  punch  to  correct  height  and 
shape,  and  reharden,  with  the  possibility  of  the  punch  going  out  of  round. 
Still,  this  method  is  practical  when  the  setting  is  too  small  to  permit  of  the 


FIG.  243  FIG.  244  FIG.  242 

FIGS.  242-244.  —  Application  of  "pinch  off"  dies 


;     i ' 

m 


DRAWING  DIES  AND  THEIR  ACTION  UPON   MATERIALS      187 

use  of  the  loose  draw  punch  or  where  so  few  pieces  are  wanted  that  it  would 
not  pay  to  go  to  the  expense  of  making  the  improved  type  of  punch. 

It  will  be  found  necessary  to  shear  the  stock  somewhat  wider  than  in 
general  practice  for  plain  blanking,  and  this  amount  can  be  determined  only 
by  trial.  The  stripper  should  be  milled  with  little  more  than  enough  room 
for  the  stock  to  pass.  This  will  hold  the  stock  flat  and  prevent  wrinkling,  to 
some  extent.  With  the  feed  rolls  tight  and  the  dies  made  right,  this  will 
be  found  a  very  cheap  and  satisfactory  way  of  making  shallow  shells. 

OTHER  APPLICATIONS  OF.  THE  PINCH  OFF  PRINCIPLE 

This  principle  of  draw  and  pinch  off  tools  can  be  applied  advanta- 
geously to  other  work.  Consider  for  the  moment  Fig.  244,  which  is  the 
powder  box  for  which  the  cover,  Fig.  242,  is  made.  This  box  is  finished 
sV  in.  deep  and  crowned  on  the  bottom  the  same  as  the  cover.  On  a 
double  acting  cam  actuated  press,  the  box  is  first  drawn  about  J?  in.  larger 
in  diameter  than  finish 
size.  Then  it  is  redrawn 
and  pinched  off  to  the 
proper  height.  A  very 
satisfactory  result  is  ob- 
tained and  no  further  trim- 
ming is  necessary  if  the 
punch  is  kept  sharp. 

This  type  of  punch  and  f      J ___j^       \ 

die  can  very  often  be  used  „       4_  F      24g          FIG  247 

to  advantage  in  drawing  _       .     v     .        ,  (t,  „„ 

&  FIGS.  245-247. — Application  of  "  knock  off  " 

and  trimming  steel  shells 

for  various  purposes.  In  Fig.  245  is  shown  a  cup  made  of  0.0437  sheet 
steel,  drawn  upon  a  cam  actuated  cut-and-draw  press  and  then  redrawn  to 
the  dimensions  given.  After  annealing  it  had  been  the  practice  to  turn  or 
face  off  in  a  drilling  machine,  the  cup  being  held  in  special  jaws  while  the 
cutting  tool  was  fastened  in  the  spindle.  The  cup  was  then  put  through  a 
final  draw  and  again  sent  to  the  drilling  machine  to  be  faced  off  to  correct 
height,  as  shown  at  Fig.  246.  As  may  be  supposed,  there  were  many  rejec- 
tions due  to  the  facing  off  of  too  much  material  or  to  rough  edges.  In  the 
latter  case  it  was  necessary  to  send  the  pieces  to  the  polishing  room  to  be 
ground,  all  of  which  tended  to  increase  the  cost  of  production. 

To  avQid  further  trouble  of  this  character,  a  punch  was  made  like  the 
one  in  Fig.  243.  The  results  were  very  satisfactory  so  far  as  the  finished 
cups  were  concerned.  While  the  draw  punch  was  new  and  smooth,  the 
work  stripped  off  without  any  trouble  but  as  soon  as  the  punch  became 
roughened  a  little  the  shells  began  to  stick.  So  a  special  stripper  or  knock 
off  was  applied  as  in  Fig.  247. 


I 


188  PUNCHES  AND   DIES 

This  consists  of  a  central  plunger  which  is  connected  to  the  arm  seen 
projecting  from  the  side  of  the  punch.  The  end  of  this  arm  strikes  the  top 
of  the  die  as  the  punch  descends  just  after  the  trimmed  cup  has  passed 
through  the  drawing  die  and  is  free  to  be  stripped  off  of  the  punch.  As  the 
punch  is  permitted  to  continue  on  through  the  die  for  a  short  distance  the 
cup  is  started  or  forced  off  for  about  1  in.  and  as  the  punch  is  withdrawn,  is 
stripped  clear  off  by  the  shear  edge  of  the  draw  die. 

This  device  operates  with  entire  satisfaction  and  is  the  means  of  saving 
two  facing  operations  in  the  drill  press  with  the  usual  losses. 

MAKING  A  FUNNEL  SHAPED  SHELL 

Thus  far  the  dies  illustrated  in  this  chapter  have  been  for  producing 
cylindrical  shells  and  similar  articles  with  straight  walls;  but  such  objects 
form  only  a  part  of  the  work  for  which  drawing  dies  are  regularly  used. 
They  are  quite  as  applicable  to  the  making  of  conical  shaped  articles, 


FIG.  248.  —  Tools  for  a  conical  shell 

square  and  rectangular  boxes  and  shells,  and  irregular  parts  of  too  great 
a  variety  to  even  designate  by  title.  Frequently  the  drawing  process  is 
utilized  for  one  or  more  steps  in  a  sequence  involving  the  application  of 
forming  and  bending  dies,  trimming  tools,  and  other  press  appliances  of 
like  nature,  each  doing  its  part  of  the  work  in  advancing  the  article  toward 
completion. 

Drawing  dies  are  frequently  used  in  gangs  for  multiple  production. 
They  are  also  arranged  on  the  progressive  plan  with  other  tools  which  are 
required  for  performing  a  preceding  or  a  subsequent  operation.  In  the 
form  of  combination  dies  they  are  used  in  almost  endless  variety.. 

The  tools  in  Figs.  248  and  249  are  a  set  for  making  the  oone  shaped  or 
funnel  formed  article  shown  in  detail  in  Fig.  250.  This  is  a  piece  used  in  a 
coin  register  and  it  is  made  from  0.032  in.  steel.  It  is  three  inches  diameter 
at  the  large  end  and  at  the  small  end  there  is  a  f  f  in.  nose  drawn  up  to  a 
height  of  J  in. 


DRAWING  DIES  AND  THEIR  ACTION  UPON   MATERIALS       189 


The  work  starts  with  the  production  of  a  blank  in  the  dies,  shown  in 
Fig.  248,  which  cut  out  a  disk  3J  in.  diameter.  Then  the  work  goes  into 
the  dies  in  Fig.  249  where  the  flat  blank  is  cupped  or  drawn  up  to  the  ap- 
proximate size  wanted  but  with  the  smaller  end  rounded  to  the  curve  in- 
dicated at  A,  Fig.  250.  Tfrs  end  is  then  brought  up  to  the  form  B  and 


FIG.  249.  —  Tools  for  a  cone-shaped  article 


No.17  - 1  Req. 
.032  "x.  SH"x  4  "Steel 


FIG.  250.  —  Detail  of  cone  shell 

the  hole  pierced  in  the  point  by  the  tools  at  the  right  in  Fig.  249,  which 
are  adapted  to  operate  on  the  top  half  only  of  the  work.  Then  the  finish 
tools  at  the  left  in  this  photograph  set  the  whole  cone  up  firmly  to  the 
shape  of  the  conical  lower  die  and  open  the  hole  and  finish  the  collar  or 
nose  on  the  end  of  the  piece. 

With  the  exception  of  the  last  set  of  dies  all  of  the  tools  on  this  work  are 
of  the  open  type  but  the  finishing  dies  are  of  the  subpressed  order  or  made 
with  pillars  for  alinement  in  operation. 


190  PUNCHES  AND  DIES 

AN  IRREGULAR  OIL  CAN  SPOUT 

As  an  example  of  an  irregular  piece  of  drawing  work  the  oil  can  spout 
in  Fig.  251  is  referred  to  here.  This  illustration  represents  the  spout  in 
various  stages  from  start  to  finish.  The  tools  are  shown  by  Figs.  252  to 
256  inclusive. 

The  drawn  object  is  made  in  nine  operations  and  two  anneals.  There 
are  five  draw,  one  stamping,  and  three  trimming  operations.  The  metal  is 
brass  0.020  in.  thick,  the  blank  being  4.5  X  3.250  in.  By  placing  the  set 
edges  A,  Fig.  252,  at  70  degrees  to  the  center  line  B-C,  a  strip  4.25  in.  was 
used  as  stock. 

The  first  operation  is  accomplished  on  a  small  cam  drawing  press. 
Coming  from  this  the  diameter  of  the  shell  is  1.75  in.  and  the  depth  1J 


FIG.  251.  —  Steps  in  making  an  oil  can  spout 

in.  The  production  on  this  operation  is  15,OQp  per  day.  It  has  been 
found  that  there  is  an  advantage  in  making  the  drawing  die  of  a  separate 
piece  of  steel  from  the  cutting  die  as  shown  in  Fig.  252.  When  the  draw- 
ing die  becomes  worn  and  has  to  be  reground,  this  can  be  attended  to  by 
taking  it  apart  and  grinding  the  drawing  and  the  cutting  dies  separately. 

The  second  drawing  operation  is  performed  with  a  single  acting  reducing 
die,  Fig.  253,  the  shell  being  reduced  to  1.5  in.  in  diameter  for  1  in.  of  its 
depth.  In  this  operation  a  ratchet  dial  feed  is  used  and  the  production  is 
25,000  per  day. 

The  third  drawing  operation  is  made  possible  by  the  reducing  die,  Fig, 
254,  having  the  slide  A  placed  on  the  side  where  the  spout  is  to  be  formed. 
This  slide  has  tension  on  it  caused  by  springs  B.  As  the  punch  C  descends 
the  lip  D  presses  against  the  metal  left  to  form  the  spout  which  pushes  the 
slide  A.  This  slide  acting  upon  the  principle  of  a  jumper  ring  in  a  combi- 
nation drawing  die,  keeps  the  metal  smooth  in  the  spout  while  it  is  being 
formed  to  shape.  In  this  operation  a  ratchet  dial  feed  is  used  and  the 
production  is  25,000  per  day. 

The  fourth  operation  is  done  in  a  single  acting  reducing  die  like  Fig. 
253.  The  shell  is  here  reduced  to  1.25  in.  in  diameter  for  0.5  in.  of  its 
length.  The  same  type  of  feed  is  employed  as  for  the  previous  operation 
and  the  same  rate  of  production  is  obtained. 


DRAWING  DIES  AND  THEIR  ACTION  UPON   MATERIALS       191 


192  PUNCHES  AND  DIES 

The  fifth  operation  is  performed  with  the  reducing  die,  Fig.  255.  The 
cylinder  of  the  shell  is  reduced  to  1.25  in.  diameter.  Feed  and  production 
are  as  before.  The  sixth  operation  is  performed  in  a  stamping  die  set  in 
the  crank  press.  Here  again  the  same  ratchet  feed  is  used  and  the  same 
rate  of  25,000  pieces  per  day  is  obtained. 

The  trimming  of  the  shell  is  done  in  three  operations :  First  the  nose 
and  air  vent  are  trimmed  in  one  operation  by  the  punches  A  and  B,  Fig. 
256,  the  punch  A  being  made  with  a  V-shaped  cutting  edge  to  fit  the  spout, 
and  the  punch  B  with  a  cutting  edge  to  fit  the  air  vent  of  the  shell.  In  the 
second  trimming  operation  one  side  is  trimmed  in  the  die  E,  Fig.  256.  The 
third  trimming  operation  is  performed  in  a  die  similarly  made,  but  the 
reverse  of  die  E. 

Foot  presses  are  used  in  all  of  the  trimming  operations  and  a  production 
of  10,000  a  day  is  secured  with  each  operation.  Soap  water  is  the  lubri- 
cant used  on  all  of  the  drawing  operations. 

PECULIARITIES  OF  SQUARE  DRAWING  DIES 

Reference  may  be  briefly  made  here  to  some  of  the  special  features  in 
the  construction  of  drawing  dies  for  square  and  rectangular  work.  Im- 
proper tool  designing  for  boxes  of  these  forms  will  more  seriously  affect  the 
product  than  in  the  case  of  plairi"  cups  and  shells,  and  the  following  sugges- 
tions may  be  of  service  to  those  who  now  and  then  have  work  of  this  nature 
to  look  after. 

Difficulty  is  frequently  encountered  in  drawing  rectangular  shapes 
even  though  the  tools  may  be  to  all  appearances  excellent  examples  of  that 
class  of  die  work,  due  principally  to  the  fact  that  the  radii  of  the  corners 
and  edges  are  not  given  due  consideration.  These  radii  are  of  the  greatest 
importance  when  designing  such  tools  and  should  be  made  as  large  as  the 
shape  to  be  drawn  will  permit.  The  drawing  at  the  sides  of  the  work  is 
similar  to  a  bending  operation  and  the  greatest  stress  upon  material  and 
tools  occurs  at  the  corners  of  the  die.  Should  a  box  be  required  in  which  a 
corner  radius  of  f  in.  is  permissible  it  is  unnecessary  to  make  it  smaller. 

The  quality  of  metal  used  should  receive  due  consideration,  and  in  case 
of  failure  a  set  of  dies  should  not  be  too  hastily  condemned  or  the  operation 
pronounced  impracticable  when  it  may  be  the  material  that  is  at  fault. 

The  radius  of  the  drawing  edge  of  the  die  should  be  uniform  and  smooth, 
the  corners  very  hard  and  the  top  surface  entirely  free  from  grinding  marks. 
Slightly  more  than  the  required  amount  of  material  thickness  should  be 
allowed  for  at  the  corners,  as  this  reduces  the  amount  of  pressure  and  con- 
sequent wear  on  the  die  which  will  occur  principally  at  these  points.  As 
stated,  the  radius  of  the  drawing  edge  should  be  as  large  as  possible,  but  if 
material  is  released  from  under  the  pressure  pad  or  blank  holder  too  rapidly, 
wrinkling  will  take  place,  probably  resulting  in  fracture  of  the  material  or 


DRAWING  DIES  AND  THEIR  ACTION   UPON   MATERIALS       193 


First  Draw 


First  Draw 


FIG.  25  7 


FIG. 25 8 

FIGS.  257-258.  —  Corners  in 
square  and  rectangular  dies 


in  jagged  corners.  For  thick  stock  this  radius  can  be  quite  large,  but  for 
thin  stock  it  should  be  small.  A  good  rule  is  to  make  the  radius  about  six 
or  eight  times  the  thickness  of  the  material  used. 

When  it  is  not  practical  to  draw  a  box  in  one  operation  the  corner 
radius  of  the  first  draw  should  be  approximately  four  times  the  required 
radius  of  the  finished  shell.  In  order  to  illustrate  more  clearly  the  right  and 
wrong  method  of  design,  the  corner  radius  of 
first  and  second  operation  dies  is  shown  in 
Fig.  257.  At  A  the  radii  for  both  operations 
are  drawn  from  the  same  center.  At  B  is 
shown  the  proper  method.  Note  that  the 
radius  is  described  from  a  different  center 
for  each  die. 

When  a  die  maker  not  familiar  with  this 
class  of  work  is  called  upon  to  determine  the 
required  blank  size  he  not  infrequently  makes 
the  trial  blank  as  shown  by  full  lines  in  Fig. 
258,  but  after  repeated  trials  he  will  reach 
the  conclusion  that  the  shape  as  shown  by 
dotted  lines  is  more  nearly  correct.  A 
method  of  eliminating  some  of  these  trial 
blanks  and  arriving  at  once  at  the  proper  shape  and  size  for  work  of 
this  character  will  be  found  in  another  section  of  this  book  (p.  369) 
relating  directly  to  the  finding  of  blank  sizes  and  to  lay  out  operations 
in  general. 

DRAWING  WORK  INSIDE  OUT 

It  is  occasionally  desirable  to  redraw  work  by  turning  it  inside  out,  thus 
securing  a  greater  degree  of  elongation  at  each  operation.  An  example  of  a 
shell  made  in  this  manner  is  illustrated  herewith  with  the  dies  for  performing 
the  series  of  operations  required  in  making  this  shell,  which  finishes  to  a 
length  of  6f  in.  and  an  inside  diameter  of  lif  in.,  the  wall  being  0.028  in. 
thick.  The  material  is  Britannia  white  metal. 

The  work  is  performed  in  four  dies  and  comes  out  of  the  operations 
with  a  highly  polished  surface.  The  dies  are  shown  in  Figs.  259  to  262 
inclusive  with  the  progress  of  the  shell  indicated  in  each  view  by  a  detail 
sketch. 

These  sketches  of  the  dies  are  practically  self-explanatory  but  a  brief 
outline  of  the  operations  may  be  of  value.  The  cutting  and  drawing  dies, 
Fig.  259,  are  used  in  a  double  action  press  with  a  blank  6J  in.  square  and 
0.094  in.  thick.  These  first  dies  give  a  cup  3  in.  in  diameter  by  2J  in. 
high  but  do  not  thin  down  the  walls  at  all  as  the  difference  between  the 
punch  diameter  and  the  die  is  made  just  twice  the  thickness  of  the  blank. 


194 


PUNCHES  AND   DIES 


During  some  earlier  experiments  with  this  work  good  results  were 
secured  until  the  final  operations  were  reached;  then  the  percentage  of 
broken  pieces  would  be  anywhere  between  50  and  75  per  cent,  sometimes 
more.  That  was  with  the  ordinary  method  of  redrawing.  Then  it  was 
decided  to  try  to  turn  the  preceding  cup  wrong  side  out,  so  the  second 
and  third  operation  redrawing  dies  were  made  pn  that  principle  and  there- 
after there  was  practically  no  trouble. 

The  second,  third,  and  fourth  dies  can  be  used  in  any  ordinary  single 
action  press,  provided  the  stroke  is  long  enough. 

The  dies,  Fig.  260,  for  the  second  operation  bring  the  walls  of  the  tube 
down  to  0.037  in.  thick  and  lengthen  it  to  3J  in.  The  cup  after  passing 


Thread  to  Attach  Shank 


2.27 


Cutting 
„    Edge 
.312  Radius 
T.S. Cutting 
Ring 

M.S. Die 
C.I. Shoe 


C.I.  Shoe 


M.S. Blank  Holder 
M.S.Punch     1^.3.00"^ 

Air  Vent     |  |[V 

.250 

jr_ 

^U89"1 

The  Work 


FIG.  25 9       1st  Operation 

Cut  and  Draw  Dies 

// 

1.812 


^2.1   . 

2nd  Operation      FlG.260 
1st  Redraw  Die  < 

noo 
1,812' 


The  Work 


3rd  Operation 
2nd  Redraw  Die 


C.I.  Shoe 


T.S.Punch 
Hdn.&  Gr. 

1.187  Rad 
4"       „ 
4-  1.868 
-T.S. Die 
4  Spring  Fingers 
-4  Springs 


I  The 
JFiniBhed 
Work 


Fic.261 
FIGS.  259-262.  —  Drawing  tubes  inside  out 


1.937- 

4th  Operation 
Crd  Redraw 


Screw 

Fic.262 


through  the  first  operation  dies  is  inverted  over  the  die  for  the  second  oper- 
ation. This  die  is  made  0.010  in.  smaller  on  the  outside  than  the  inside 
diameter  of  the  work  to  facilitate  matters  when  feeding,  as  the  press  can 
be  run  continuously,  the  work  dropping  down  through  the  center  of  the 
die  into  a  box. 

THIRD  AND  FOURTH  DRAWS 

The  third  operation,  Fig.  261,  consists  of  the  same  operation  as  in  the 
second,  only  the  die  is  made  to  draw  the  work  down  to  the  required  inside 
diameter  with  walls  0.034  in.  thick,  giving  a  shell  5|  in.  long. 

The  punch  for  the  third  operation  is  used  on  the  fourth  or  final  draw, 


DRAWING  DIES  AND  THEIR  ACTION  UPON  MATERIALS       195 

and  the  die  is  made  as  in  Fig.  262.  This  completes  the  work,  making  a 
shell  or  tube  1  jf  in.  diameter,  6|  in.  long,  and  0.028  in.  thick  through  the 
walls,  with  a  high  polish  on  the  outside.  Of  course  the  die  has  to  be  highly 
polished  to  give  these  results,  and  the  punch  is  hardened,  ground,  and  lapped 
as  the  work  after  passing  through  this  last  die  holds  tightly  to  the  punch. 

The  dies  for  the  first,  second,  and  third  operations  are  made  of  machine 
steel  and  left  soft,  but  polished,  and  the  cutting  ring  for  the  first  operation 
is  of  tool  steel  but  is  not  hardened. 

The  work  automatically  strips  itself  from  the  punches  in  the  first  three 
operations,  as  there  is  a  little  outward  spring  to  the  top  walls  of  the  work. 
In  the  last-operation  dies,  four  spring  fingers  are  placed  around  the  die, 
to  just  let  the  punch  through  without  touching.  When  the  work  is  on  the 
punch,  these  fingers  spring  downward  and  over  the  top,  thus  stripping  it 
off  the  punch  on  the  upward  stroke. 

The  only  lubricant  used  on  these  four  operations  is  a  mixture  of  soft 
soap,  soda,  lard  oil,  and  water,  all  boiled  together  and  left  to  cool  before 
using. 

The  uneven  ends  of  the  work  are  not  trued  up  between  operations,  as 
this  is  unnecessary  and  would  only  waste  stock  and  shorten  the  final  tube. 
The  work  is  not  annealed  or  touched  between  operations. 

i 
GANG  DRAWING  DIES  FOR  STEEL  THIMBLES 

As  stated  before,  drawing  dies  are  frequently  arranged  in  gangs  for 
convenience  of  operation  and  for  high  production.  An  example  is  seen 
in  the  accompanying  outfit  for  manufacturing  the  steel  thimble  shown  in 
Fig.  263  herewith. 

This  thimble  is  made  of  No.  14  gage  cold  rolled  stock.  It  must  be  held 
close  to  the  required  dimensions  and  is  made  in  five  operations  without 
annealing.  The  walls  must  be  held  to  original  thickness.  By  making  the 
thimble  in  five  operations  the  reduction  is  gradual  and  the  stock  is  less 
strained,  thus  preventing  the  stretch  that  would  otherwise  occur. 

Subpress  dies,  or  dies  with  guide  pillars,  are  used  to  facilitate  the  die 
setting,  and  fewer  presses  are  necessary  to  start  the  work.  In  this  way  the 
presses  can  be  set  up  and  the  finished  article  turned  out  in  a  very  short 
time  as  compared  with  the  usual  method  of  running  a  single  operation  on 
a  press.  The  drawing  dies  are  operated  in  two  small  presses  set  close 
together.  The  blanking  and  cupping  operation  is  performed  in  an  inclined 
press. 

The  punch  C,  Fig.  264,  serves  a  double  purpose.  As  it  descends  it 
cuts  the  blank,  which  is  held  between  its  face  and  the  pressure  plate  /. 
As  it  descends  further,  the  blank  is  forced  by  the  punch  H  through  the 
central  hole  in  C,  thus  forming  the  cup.  The  pressure  on  the  plate  / 
is  obtained  from  the  pins  K  and  the  rubber  bumper  X.  The  required 


196 


PUNCHES  AND  DIES 


DRAWING  DIES  AND  THEIR  ACTION   UPON  MATERIALS       197 

regulation  of  pressure  on  the  plate  J  is  obtained  in  the  usual  way  by  the  stud 
L  and  the  nut  N.  The  blanking  die  F  is  held  by  screws  G.  The  cup  is 
carried  up  into  the  cavity  in  the  punch  C  and  as  this  die  is  used  on  an  in- 
clined press,  the  cups  roll  out  of  the  opening  at  the  back  and  into  a  recep- 
tacle, being  forced  out  by  the  succeeding  cups  as  they  are  formed.  At  no 
time  are  there  more  than  two  cups  in  the  cavity.  - 

The  lower  punch  is  vented  at  0  so  that  the  cups  will  strip  readily. 
The  production  on  this  operation  is  3000  pieces  per  hour. 

FOLLOWING  OPERATIONS 

The  second,  third,  fourth,  and  fifth  operations  are  now  put  through  the 
die  shown  in  Fig.  265,  whereby  the  operator  transfers  the  operations  in 
proper  rotation  from  one  die  to  another,  keeping  all  dies  supplied.  Tha 
capacity  of  this  die  is  1000  pieces  per  hour. 

In  Fig.  265  is  shown  the  front  view  of  the  gang  dies  for  the  four  final 
operations.  The  punch  holder  A  and  the  die  holder  B  are  kept  in  proper 
alinement  with  each  other  by  guide  pins. 

The  shell  B  (Fig.  263)  is  drawn  in  the  second  operation  die  F  by  the 
punch  G.  This  punch  has  an  air  hole  to  allow  easy  stripping.  The  shell 
C  (Fig.  263)  is  drawn  in  the  third  operation  die  H  by  the  punch  7.  This 
punch  has  an  air  hole  at  0.  The  shell  D  is  drawn  in  the  fourth  operation 
die  J  by  the  punch  K,  a  45-degree  angle  flange  being  bulged  in  the  bottom 
and  a  -fa  in.  hole  punched.  The  shell  E  is  trimmed  on  the  flange  in  the 
fifth  operation  die  L  by  the  punch  M . 

The  stripper  N  is  held  in  place  by  the  screws  SS,  which  are  long  enough 
to  give  the  stripper  the  proper  movement  to  release  the  shells  from  the 
punches  with  the  aid  of  the  lower  knockout  plate  T.  This  stripper  is 
fitted  with  carbon  steel  bushings  screwed  into  place.  The  knock  out  plate 
T  also  releases  any  shells  from  the  dies  by  giving  the  knock  out  pins  Y  and 
Z  the  proper  movement.  The  stripper  bolts  U  are  adjusted  in  relation  to 
the  stroke  of  the  press. 

The  punches  G,  7,  K,  and  M  are  held  in  position  by  tapered  pins  V. 
The  punch  K  has  a  perforating  punch  W  inserted  to  perforate  the  bottom 
of  the  shell  and  must  be  adjusted  to  suit  the  thickness  of  the  metal  in 
order  that  it  may  not  go  through  too  far  before  the  forming  of  the  bot- 
tom takes  place.  The  dies  F}  H,  J,  and  L  are  held  in  position  by  the 
screws  X.  The  knockout  pin  Z  in  addition  to  acting  as  such  also  serves 
as  a  perforating  die  for  the  fourth  operation. 

PROGRESSIVE  DIES  FOR  AN  AUTOMOBILE  HUB 

The  manufacture  of  a  pressed  steel  automobile  hub  as  carried  out  by 
means  of  the  following  tools  forms  an  interesting  illustration  of  the  ap- 
plication (among  other  types)  of  the  progressive  arrangement  of  dies  for 
certain  kinds  of  drawing  operations.  This  steel  hub,  as  shown  in  Fig.  266, 
is  drawn  from  a  cold  rolled  blank  13|  in.  diameter  and  J  in.  thick.  It  is 


198 


PUNCHES  AND  DIES 


finished  in  10  operations.     Several  of  the  dies  are  of  the  tandem  order  which 
increases  production  and  decreases  the  number  of  presses  used. 

The  tandem  drawing  dies  are  set  upon  double  acting  presses.  They 
can  be  operated  by  one  operator  but  two  are  required  when  the  greatest 
possible  output  is  desired.  When  two  operators  are  engaged  on  one  press, 
an  electric  device  with  four  pushbuttons  is  put  in  action,  whereby  both 
operators  must  touch  the  four  buttons  in  unison  before  the  press  can  be 


FIG.  266.  —  Successive  steps  in  drawing  a  pressed  steel  hub 

brought  into  action  by  a  foot  treadle  controlled  by  one  of  the  operators. 
This  arrangement  protects  both  operators  from  being  injured  in  any  way. 

As  mentioned  elsewhere,,  it  is  customary  in  most  plants  making  pressed 
steel  articles  to  draw  shells  with  dies  that  have  only  enough  clearance  be- 
tween punch  and  die  for  the  thickness  of  the  stock,  the  punch  being  made 
twice  the  thickness  of  the  stock  smaller  than  the  die  diameter.  This  is  not 
always  practicable  where  heavy  material  is  drawn,  where  strength  is  more 
desirable  and  uniformity  of  wall  thickness  of  less  importance. 

The  first  four  operations  on  this  hub  are  handled  in  drawing  dies  that 
are  •£?  in.  large.  The  dies  work  easily  and  keep  free  from  scratches.  This 
saves  much  time  usually  taken  to  polish  the  radius.  The  stampings  release 
with  less  friction  when  made  under  these  conditions  and  the  stock  being 


DRAWING  DIES  AND  THEIR  ACTION  UPON  MATERIALS       199 

subjected  to  lower  stress  will  admit  of  passing  through  more  operations 
without  annealing.  The  walls  of  the  shell  are  apt  to  thicken  up  and  this 
is  desirable  where  strength  is  required.  Necessarily,  the  production  from 
dies  operated  under  these  conditions  is  greater. 

The  first  two  operations  shown  at  A  and  B,  Fig.  266,  are  the  blanking 
and  drawing  on  the  dies  in  Fig.  267,  operations  1  and  2.  The  stamping 
A  when  blanked  and  drawn  is  transferred  from  the  first  operation  to  the 
second  operation  die,  which  reduces  its  diameter  to  4f  in.  and  turns  the 
stamping  completely  inside  out.  Whenever  it  is  possible  to  apply  this 


FIG.  267.  —  First  and  second  operations 

method  it  should  be  adopted,  as  with  it  a  greater  reduction  in  diameter  is 
effected.  j>|  | 

The  tandem  dies  in  Fig.  267  are  made  of  steel  sections  set  in  cast  iron 
plates  A  and  B.  To  facilitate  setting  up  of  the  dies  the  guide  pins  C  are 
added  and  held  in  position  by  the  set  screws  D.  The  guide  pins  are  made 
of  hardened  tool  steel  and  are  ground  0.002  in.  smaller  than  the  bronze 
bushings  E.  The  bushings  E  have  at  F  recesses  that  are  filled  with  a 
mixture  of  machine  oil  and  white  lead  to  lubricate  the  guide  pins  C. 

Referring  to  the  first  operation  dies,  the  blanking  punch  G  is  held  in 
place  by  the  screws  K.  The  blanking  die  H  is  held  by  screws  R.  Both 
punch  and  die  are  made  of  tool  steel  hardened.  The  punch  G  is  hollow  and 
allows  the  punch  I  to  enter  it  as  it  descends.  The  blank  from  H  and  G 
is  formed  between  I  and  G  to  the  shape  shown  at  A,  Fig.  266.  The  punch 
/  is  held  in  place  by  the  nut  L.  The  pressure  plate  /  is  made  of  hardened 
tool  steel.  It  prevents  wrinkles  in  the  work  and  at  the  same  time\acts  as 
a  knockout  to  raise  the  work  out  of  the  die  and  to  a  position  where  the 
operator  can  quickly  transfer  it  to  the  second  operation  die. 


200 


PUNCHES  AND  DIES 


The  pressure  on  J  is  controlled  by  the  rubber  bumper  M.  Adjust- 
ments of  the  pressure  are  made  by  tightening  the  nuts  S  against  the  plates 
0.  Care  must  ,be  exercised  in  adjusting  this  pressure  pad  as  too  much 
pressure  on  it  may  strain  the  work  on  the  radius  and  cause  it  to  break  when 
subjected  to  succeding  operations. 

The  gages  X  are  tool  steel,  hardened.  The  rear  gage  must  be  set  to 
the  edge  of  the  die  in  order  to  allow  the  steel  to  part  and  open.  This 
prevents  the  steel  from  holding  to  the  punch,  obviating  the  necessity  for  a 
stripper  plate  on  the  die. 

THE  SECOND  OPERATION  DIES 

The  second  operation  dies  operate  in  the  same  manner  as  those  for  the 
first  operation.  C  is  the  punch,  held  in  place  by  a  taper  pin  D.  The  die 
E  is  secured  by  the  screws  F.  Both  punch  and  die  are  made  of  tool  steel, 


FIG.  268.  —  Third,  fourth  and  fifth  operations 

hardened.  The  stripper  G  acts  also  as  a  pressure  pad  and  is  held  in  place 
by  the  screws  H.  It  is  given  the  proper  pressure  and  ejecting  action  by 
the  springs  /.  The  knockout  J,  which  discharges  the  stamping  from  the 
die  is  made  of  tool  steel,  hardened.  It  is  actuated  by  the  pins  K  and  plates 
L  when  the  rubber  bumper  M  is  properly  adjusted  by  the  bolt  and  nut  N. 

The  shoe  A  has  T-slots  Z  to  fasten  it  to  the  ram  of  the  press.  The 
stampings  CDE,  Fig.  266,  are  reduced  from  4f  to  2jf  in.  diameter  in 
three  operations.  The  work  is  drawn  on  tandem  dies  shown  in  Fig.  268. 
This  die  also  is  operated  in  a  double  crank  press.  The  shoe  or  punch 
casting  A  is  made  of  cast  steel  and  the  shoe  B  of  cast  iron  set  with  steel 
dies  and  punches.  These  are  guided  by  the  pins  C,  held  by  set  screws  D, 
and  ride  with  the  necessary  freedom  in  the  bronze  bushing  G.  The  dies 
H  are  of  tool  steel,  hardened;  they  are  held  in  place  by  screws  7. 

The  stripper  plate  J  has  hardened  bushings  K  which  act  as  pressure 


DRAWING  DIES  AND  THEIR  ACTION  UPON   MATERIALS      201 

pads  to  flatten  the  flanges  of  the  work.  The  stripper  is  held  by  the  bolts 
M,  which  carry  the  lower  plate  N.  This  lower  plate  is  so  adjusted  that 
it  gives  the  shoulder  knockout  0  the  proper  travel  to  expel  the  stampings 
CDE,  Fig.  266,  when  the  ram  is  on  its  upward  stroke.  The  T-slots  P  are 
for  securing  the  punch  to  the  ram  of  the  press. 

THE  SIXTH  OPERATION  DIES 

The  stampings  E  are  now  annealed  and  pickled  to  remove  all  scale 
before  they  are  put  through  the  sixth  operation  dies,  shown  in  Fig.  269. 
Here  they  are  formed  into  a  hub  8J  in.  in  diameter  and  the  bottom  is 
indented.  The  indentation  die  is  necessary  to  shorten  the  hub  to  fit  the 


FIG.  269.  —  Sixth  operation 

succeeding  die,  as  well  as  to  supply  the  much  needed  stock  that  is  necessary 
for  bulging  in  a  later  operation. 

At  A,  Fig.  269,  is  the  punch,  which  is  made  of  tool  steel,  hardened. 
The  stud  B  has  a  hole  X  through  the  shank  to  secure  it  to  the  ram.  It  is 
threaded  on  the  opposite  end  to  hold  together  the  sections  BCD.  The 
shoe  E  is  of  cast  iron  and  serves  to  hold  the  dies  that  are  made  in  sections. 
The  forming  die  F  is  secured  by  screws  G  and  is  of  tool  steel,  hardened. 
The  bushing  H,  held  by  screws  7,  is  also  of  hardened  tool  steel  and  serves 
to  guide  the  hub  in  its  downward  course  to  indent  the  bottom  with  the 
tool  steel  hardened  punch  J.  A  tool  steel  hardened  ring  K  acts  as  a  knock 
out,  should  the  hub  stay  in  the  die.  The  stripper  L,  which  also  serves  to 
flatten  the  flange  of  the  hub,  is  made  of  machine  steel  and  has  a  hardened 
tool  steel  ring  M,  which  is  held  in  position  by  screws  N. 


202 


PUNCHES  AND  DIES 


The  stripper  L,  which  is  free  to  slide  on  the  punch  A,  must  be  held  to  the 
ram  by  bolts  and  given  the  proper  sliding  adjustment.  The  tapped  holes 
0  are  provided  for  securing  it  to  the  press  ram.  The  rods  P  are  screwed 
to  the  stripper  pad  L  and  carry  the  knockout  plate  R  underneath  the  die. 

The  knockout  ring  K  is  fastened  to  the  plate  R  by  the  bolts  S  and  when 
properly  adjusted  works  as  a  unit  in  connection  with  the  stud  J  to  release 
the  hub  on  its  upward  stroke.  The  holes  T  in  the  die  serve  as  a  means  for 
bolting  it  to  the  press. 

THE  BULGING  PROCESS 

The  hub  F,  Fig.  266,  is  now  put  through  the  oil  bulging  dies.  This  is 
the  seventh  operation  and  is  shown  in  Fig.  270.  The  end  is  bulged  out 
until  it  fills  the  cavity  Z  in  the  die,  forming  the  necessary  end.  The 


FIG.  270.  —  Seventh  operation 

flanges  are  also  squared  in  this  operation.  The  hub  should  be  0.010  in. 
small  at  0  in  the  dies,  so  that  the  punch  X  when  entering  the  hub  will 
expand  it  to  size.  There  being  no  escape  for  the  oil  because  of  the  tight 
fit  of  the  punch  in  the  work,  the  hub  will  be  bulged  out  until  it  fills  the 
cavity  Z  in  the  die. 

The  punch  A  is  made  of  machine  steel  with  a  hardened  plate  B  held  by 
the  screws  C.  This  plate  serves  to  flatten  the  flanges  on  the  hub.  The 
holes  D  are  drilled  in  the  punch  and  serve  to  discharge  the  oil  from  the 
upper  part  of  the  hub.  The  point  X  is  made  of  high  speed  steel  and  can 
be  replaced  quickly  when,  through  wear,  this  becomes  necessary.  In  ad- 
dition to  the  ram  adjustment  the  adjusting  screws  E  and  the  rubber  washer 
F  must  be  set  with  care  in  order  to  regulate  the  amount  of  oil  necessary 
for  bulging.  If  the  set  screws  EE  are  too  high  in  the  punch,  the  pressure 
in  the  bottom  of  the  hub  is  decreased  to  such  an  extent  that  it  will  not  fill 


DRAWING  DIES  AND  THEIR  ACTION  UPON   MATERIALS       203 

the  cavity  Z;  and  if  the  screws  are  too  low  in  the  punch,  there  is  too  much 
pressure,  which  might  result  in  damage  to  either  the  press  or  the  die  or 
both. 

The  die  shoe  G  is  of  cast  iron  and  serves  as  a  reservoir  and  die  holder. 
The  die  H  is  made  in  halves  and  is  opened  by  the  cam  /  and  a  square  sliding 
pin  J",  assisted  by  the  springs  K.  Oil  channels  large  enough  to  discharge 
the  surplus  oil  are  provided  at  L  in  the  die  as  well  as  at  D  in  the  punch. 
The  inlet  and  outlet  pipes  M  and  N  must  be  so  placed  as  to  give  at  all  times 
the  proper  depth  of  oil  in  the  reservoir.  These  pipes  are  supplied  with 
lard  oil  through  properly  adjusted  automatic  pumps.  The  punch  is 
secured  by  a  pin  through  the^hole  P  in  the  shank.  The  holes  S  in  the  die 
serve  to  secure  the  die  to  the  press. 

PERFORATING  OPERATIONS 

The  hub  G,  Fig.  266,  having  been  finished  on  the  bulging  die,  is  now 
ready  to  be  perforated  in  the  eighth  operation  die,  shown  in  Fig.  271. 


FIG.  271.  —  Eighth  operation 

The  punch  A  is  of  cast  steel,  has  twenty-four  fVin.  punches  0,  eight  J-in. 
punches  X,  and  one  2^-m.  punch  Z. 

The  small  punches  OX  are  made  of  tool  steel,  hardened.  They  are 
driven  into  place  and  have  shoulders  backed  by  the  hard  plate  N.  The 
punch  A  has  guide  pins  B  secured  by  screws  C.  The  guide  pins  work  in 
bronze  bushings  D  seated  in  the  cast  iron  die  plate  E.  The  die  plate  E  has 
33  dies  pressed  into  place.  These  correspond  to  the  punches.  The  dies 
F  and  G  are  of  tool  steel  and  hardened. 

The  large  bushing  H  is  made  of  tool  steel,  hardened,  slightly  tapered, 


204 


PUNCHES  AND  DIES 


and  pressed  in  place.  The  small  and  large  punches  are  staggered  so  as  to 
use  as  little  power  and  be  as  easy  on  the  dies  as  possible.  The  large  punch 
Z  is  made  of  tool  steel,  hardened  and  held  in  place  by  the  screw  I.  The 
stripper  J  is  made  of  machine  steel  and  is  held  in  place  by  the  screws  K 
that  slide  in  the  punch  with  enough  freedom  to  allow  the  stripper  to  disen- 
gage the  hub  from  the  punches.  The  stripper  bolts  L  must  be  adjusted  to 
suit  the  stroke  of  the  ram.  The  holes  M  are  for  bolts  to  secure  the  die  to 
the  press  bed. 

f  The  hub  H,  Fig.  266,  having  been  perforated,  is  now  trimmed  on  the 
flange  and  beveled,  which  concludes  the  press  work.  This  operation  is 
performed  on  the  ninth  operation  die  shown  in  Fig.  272.  The  punch  holder 
A  is  made  of  cast  iron  and  has  a  stud  and  two  T-slots  B  to 'secure  it  in  the 


FIG.  272.  —  Ninth  operation 

ram.  The  holder  A  is  counterbored  to  seat  the  hardened  tool  steel,  hollow 
trimming  and  beveling  punch  C  which  is  secured  by  screws  D.  The  guide 
pins  D  slide  in  bronze  bushings  E.  The  die  plate  F  is  of  cast  iron  and  seats 
the  tool  steel  trimming  die  G,  which  is  held  by  screws  H. 

The  ring  I  is  of  tool  steel,  hardened  and  pressed  on  F.  It  acts  as  a 
beveling  die.  The  last  operation  consists  in  drilling  the  small  spoke  holes 
in  the  bulged  end  of  the  hub  and  is  performed  in  the  drill  press  with  the 
aid  of  a  jig. 

DRAWING  LARGE  WORK  OF  ALUMINUM 

The  half-tones,  Figs.  273  to  276,  illustrate  the  operation  of  a  heavy 
toggle  press  in  the  drawing  of  aluminum  ware  with  double  acting  dies. 
Details  of  the  punches  and  dies  are  given  in  Fig.  277. 

Referring  to  the  press  views,  Fig.  273  shows  the  two  slides  at  the  top 
of  their  stroke,  with  a  blank  disk  of  aluminum  on  top  of  the  die  face.  This 
blank  has  been  prepared  in  a  previous  operation  and  here  it  is  located 


DRAWING  DIES  AND  THEIR  ACTION  UPON   MATERIALS      205 


1 

I 
3 


206 


PUNCHES  AND  DIES 


3 

~i 

c 
IS 


g 

I 


DRAWING  DIES  AND  THEIR  ACTION  UPON  MATERIALS       207 


against  a  couple  of  low  stop  pins  in  the  face  of  the  die  near  the  rear  edge. 
In  some  sizes  the  equipment  is  arranged  for  blanking  and  drawing  in  the 
first  operation,  as  is  so  commonly  done  with  shell  work  in  general.  But  in 
this  instance  the  outer  slide  of  the  press  is  fitted  with  a  pressure  plate  or 
blank  holder  which  is  not  provided  with  a  cutting  edge  but  instead  is  used 
under  the  double  acting  arrangement  to  apply  the  requisite  pressure  to 
the  blank  to  prevent  it  from  wrinkling  while  it  is  being  carried  down  into 
the  die. 

In  Fig.  274,  the  outer  slide  of  the  press  is  at  the  bottom  of  its  travel  and 
the  pressure  plate  is  shown  holding  the  work  under  suitable  pressure  while 


C.J. 


--1 To  Suit  Plunger 

Blank  Holder    ,  X^TO  Suit  Plug 


Punch  I 

t^ z? H 


Dimensions    of    Tools 


1st  Op.  Die 

1st  Op.  Punch 

A=  8V16" 

•B=85£|      C=    6" 

2nd  Op.  Die 

2nd  Op.  Punch 

A=  6MZ 

B=G%\      C=  10  " 

3rd  Op.  Die 

3rd  Op.  Punch 

A-   5»/S 

B  =  53^      C=   15" 

FIG.  277.  —  Tools  for  drawing  aluminum  ware 

the  punch  is  carried  down  by  the  inner  slide  or  plunger.  In  Fig.  275  both 
outer  slide  and  inner  plunger  are  shown  rising  from  the  work,  the  punch 
of  course  being  well  cleared  before  the  pressure  plate  or  blank  holder  lifts, 
and  in  Fig.  276  the  tools  are  both  in  their  uppermost  position  and  the  work 
is  being  ejected  from  the  die  by  the  lower  knock  out,  the  arrangement  of 
which  is  clearly  shown  in  the  different  photographs. 

The  drawing,  Fig.  277,  gives  the  dimensions  of  the  dies  in  the  outfit  and 
the  sizes  of  the  punches.  The  work  is  made  from  TV-in.  aluminum  and  is 
not  reduced  in  thickness  during  the  drawing  process.  The  blank  is  13J 
in.  diameter  at  the  start  and  the  first  draw  forms  it  into  a  shell  8TV  in. 


208 


PUNCHES  AND  DIES 


outside  diameter  by  3  in.  deep.  The  second  operation  lengthens  it  to  5J 
in.  with  a  diameter  of  6J  in.  and  the  third  draw  produces  an  article  5f  in. 
diameter  by  6  in.  deep. 

The  die  proper  is  a  hardened  tool  steel  disk  1  in.  thick  which  is 
screwed  to  the  top  of  the  die  bolster.  The  radius  on  the  drawing  edge  of 
the  first  operation  die  is  f  in.  or  six  times  the  thickness  of  the  material 
drawn.  The  punches  are  hollow  as  indicated  and  are  cast  iron  cored  to 
the  interior  form  shown.  They  are  threaded  at  the  upper  end  to  suit  the 
press  plunger.  Their  lengths  are  given  in  the  table  under  the  detail 
sketches. 

CAST  IRON  DIES 

On  some  work  of  this  character  at  different  shops  the  aluminum  is 
drawn  in  cast  iron  dies,  that  is  without  the  steel  die  shown  on  top  of  the 
bolster.  It  has  been  observed  in  connection  with  such  practice  in  certain 


FIG.  278.  —  Shells  drawn  with  cast  iron  punches  and  dies 

places,  that  the  cast  iron  die  works  satisfactorily  so  far  as  general  results 
are  concerned  and  it  is  the  belief  of  some  operators  that  the  surface  of  the 
cast  iron  holds  lubricant  better  and  results  in  a  better  general  finish  for  the 
surface  of  the  object  drawn.  On  the  other  hand,  the  cast  iron  is  more 
quickly  subject  to  surface  wear  and  if  the  articles  drawn  have  to  be  held 
closely  to  diameter  this  feature  is  an  objection,  particularly  where  large 
quantities  of  similar  parts  are  produced. 

With  fairly  limited  runs,  wear  has  been  found  negligible  as  observed 
over  a  reasonable  length  of  time.  Of  course,  from  the  nature  of  much  of 
the  material  manufactured  from  aluminum  in  the  direction  of  utensils 
and  the  like,  it  is  obvious  that  no  great  degree  of  accuracy  is  essential 
(except  where  certain  pieces  must  fit  properly  together)  and  consequently 


DRAWING  DIES  AND  THEIR  ACTION  UPON  MATERIALS       209 


any  reasonable  degree. of  wear  on  the  die  may  be  overlooked  entirely  so 
long  as  the  work  is  drawn  satisfactorily  from  a  point  of  view  of  appearance. 
In  this  connection  it  may  be  stated  that  cast  iron  punches  and  dies 
have  been  used  successfully  for  drawing  steel  shells  of  moderate  size  and 
so  far  as  records  go  they  have  stood  up  to  the  work  as  long  as  the  run  lasted. 


FIG.  279.  —  Seven  operations  on  cold  rolled  steel  shell  drawn  with  cast  iron  punches 

and  dies 

Naturally  they  were  not  made  in  the  first  place  for  as  extended  a  period  of 
service  as  one  would  expect  of  a  set  of  standard  tool  steel  dies  of  the  same 
proportions.  But  for  a  fairly  large  lot  of  shells  on  a  special  order  they  have 
given  every  satisfaction. 


FIG.  280.  —  Large  east  iron  drawing  and  forming  dies 

•  The  photograph,  Fig.  278,  illustrates  the  successive  stages  of  a  steel 
shell  drawn  up  by  seven  pairs  of  cast  iron  punches  and  dies  from  a  blank 
TV  in.  thick.  The  tools  in  the  background  are  the  cupping  or  first  oper- 
ation set,  the  drawing  dies  and  punches  all  being  of  the  same  simple  de- 
sign. The  modification  in  the  shell  as  it  progresses  from  cup  to  completed 
form  is  shown  with  over-all  dimensions  in  Fig.  279. 


210 


PUNCHES  AND  DIES 


Forming  Punch  Cast  Iron 

FIG.  281.  —  Tools  for  large  metal  cover 

These  shells  all  appear  as  smoothly  drawn  as  if  the  work  were  done  in 
the  usual  steel  dies.  There  is  no  reduction  in  the  thickness  of  the  walls  of 
the  work  as  the  drawing  is  carried  along  and  all  punches  are  smaller  than 
die  diameters  by  twice  the  thickness  of  the  material. 


DRAWING  DIES  AND  THEIR  ACTION  UPON  MATERIALS      211 


LARGER  SIZES  OF  DIES  OF  CAST  IRON 

When  we  reach  the  larger  sizes  of  work,  such  as  sheet  metal  containers 
and  covers  of  various  kinds,  there  are  numerous  occasions  upon  which 
cast  iron  drawing  tools  are  made  use  of.  The  photograph,  Fig.  280,  shows 
a  few  of  a  large  number  of  such  tools  in  the  corner  of  a  press  room  and 
details  of  two  different  sets  are  reproduced  in  the  line  drawings  that  im- 
mediately follow. 

Thus,  Fig.  281  is  a  shallow  drawing  and  forming  outfit  for  the  thin 
sheet  cover,  Fig.  282,  which  is  drawn  up  from  -^  hi-  black  iron.  The 
dimensions  on  the  drawing  show  the  length  of  the  oval  shaped  piece  to  be 


FIG.  282.  —  The  work  produced  in  the  dies  in  Fig.  281 

16f  in.  The  draw  is  very  little  in  this  instance,  say  J  in.  or  so  for  the 
edge  with  a  forming  depth  for  the  circular  portion  of  about  f  in. 

The  cast  iron* draw  ring  A,  which  acts  as  a  pressure  ring  for  holding  the 
stock  against  wrinkling,  is  controlled  by  a  series  of  vertical  pins  that  ex- 
tend down  through  openings  in  the  press  bed  and  rest  upon  a  spring  plate 
secured  beneath  the  press  for  use  with  all  kinds  of  drawing  dies  of  this 
character.  This  makes  it  unnecessary  to  apply  a  special  pressure  device 
with  each  die  or  type  of  die/  The  arrangement  of  the  spring  pressure  plate 
will  be  understood  from  Fig.  283  which  shows  the  press  with  a  number  of 
the  pressure  springs  projecting  below  the  bed. 

Another  set  of  dies  made  of  cast  iron  and  used  on  this  form  of  press  are 
illustrated  at  A,  Fig.  284.  These  dies  perform  the  operations  of  drawing, 
preparatory  to  the  trimming  and  curling  of  a  metal  cover  finishing  14  in. 
inside  diameter.  The  same  style  of  tools  are  also  used  for  even  larger 
work  of  similar  character. 


212  PUNCHES  AND  DIES 


The  metal  drawn  is  No.  28  gage  (^V)  black  iron.  The  draw  from  the 
blank  is  1T9^  in.  deep  and  a  flange  is  left  by  drawing  tools  A  for  trimming 
and  wiring  in  succeeding  operations.  In  the  drawing  dies,  the  pressure 
ring  (which  is  supported  by  the  pins  B  extending  down  through  the  bed 
of  the  press  to  the  spring  plate  beneath)  is  made  of  machine  steel  but  the 
actual  drawing  members  D  and  E  are  cast  iron  only. 


FIG.  283.  —  Press,  showing  spring  plate  attached  under  bed  to  operate  pressure  pins 

in  dies 

The  steel  drawing  ring  which  is,  of  course,  left  soft,  is  recessed  across  its 
upper  face  to  form  a  seat  or  retaining  chamber  for  the  blank.  As  the  upper 
die  descends,  this  drawing  ring  is  forced  down  against  the  upward  pressure 
of  the  spring  plate  under  the  press  and  has  the  effect  of  ironing  out  the 
metal  and  preventing  the  forming  of  a  wrinkled  surface  on  the  work.  Thus 
the  full  depth  of  1T9^  in.  is  drawn  down  over  the  lower  die  without  difficulty. 


DRAWING  DIES  AND  THEIR  ACTION  UPON   MATERIALS       213 


Then  the  work  is  placed  in  the  trimming  dies  B,  Fig.  284,  for  the  shear- 
ing off  or  trimming  of  the  edge  around  the  piece. 

These  trimming  dies  have  tool  steel  cutting  edges  in  the  form  of  rings 
of  about  1J  in.  section,  which  are  made  of  tool  steel,  the  lower  one  being 
hardened,  the  upper  left  soft.  The  former  ring  is  pressed  into  its  seat 


3rd  Operation 
(Form    £  Curl) 


to  Spjcing  Plate 
Attached  to  Underside  of  Press 

No  28     VM   Black  Iron 


(Draw) 


FIG.  284.  —  Dies  for  a  large  cover 

around  the  cast  iron  base;  the  upper  ring  is  bored  a  trifle  under  size, 
warmed  enough  to  expand  slightly,  then  placed  over  the  shoulder  on  the 
upper  die  and  allowed  to  cool  and  shrink  in  place.  As  these  tools  become 
worn,  they  are  corrected  by  expanding  the  soft  upper  ring  by  peening  with 
a  hammer  and  refinishing  by  grinding  to  size. 

The  forming  and  curling  dies  are  at  C  in  the  same  drawing.     When  the 


214  PUNCHES  AND  DIES 

work  is  placed  in  the  dies,  it  rests  upon  the  top  of  cast  iron  ring  F  which  is 
held  up  by  the  spring  plate  below  the  press  bed.  When  the  top  die  A 
descends,  it  forms  the  upper  face  of  the  cover  to  the  form  of  the  dies  H  and 
at  the  same  time  the  work  is  put  under  pressure  by  the  action  of  ring  F 
so  that  as  the  upper  die  continues  to  descend  and  takes  the  pressure  ring 
along  with  it,  the  work  is  supported  properly  and  forced  to  curl  around 
the  concaved  groove  cut  around  the  entire  circle  of  the  ring  J.  The  latter 
ring  the  curling  member,  is  of  machine  steel,  and  supported  at  suitable 
height  by  being  secured  to  the  top  of  a  spacing  ring  K. 


CHAPTER  IX 

COMBINATION  AND   COMPOUND  DIES  FOR  BLANKING, 
DRAWING,  FORMING,  AND  PIERCING 

Combination  dies,  in  their  usual  form,  are  adapted  for  performing  in  a 
single  action  press  the  operations  of  cutting  a  blank,  drawing  a  shell,  form- 
ing the  end  or  edge,  beading,  etc.,  and  sometimes  a  piercing  operation  is 
included.  The  work  is  accomplished  at  a  single  stroke  of  the  press,  the 
tools  all  being  located  about  a  common  vertical  center  line  as  with  the 
compound  dies  described  in  Chapter  IV.  The  dies  carry  their  own  pressure 
pads,  drawing  rings,  and  knockouts  and  are  set  up  in  the  press  the  same  as 
a  simple  drawing  die. 


FIG.  285.  —  Combination  dies  for  blanking  and  forming  a  shallow  cover 

A  typical  construction  is  shown  in  Figs.  285  and  286  herewith.  These 
combination  tools  are  for  blanking,  drawing,  and  forming  the  cover  which 
in  finished  condition  is  shown  in  Fig.  287.  The  sketch,  Fig.  286,  shows 
the  parts  clearly.  The  blanking  die  edge  is  at  A,  the  blanking  punch  at 
B.  The  draw  post  is  at  C,  the  draw  ring  at  D.  This  rests  upon  a  set  of 
pressure  pins  E  which  extend  down  through  the  die  shoe  E  to  the  pressure 
device  G,  which  is  fitted  with  a  heavy  spring  that  is  regulated  by  nut  H 
to  apply  the  necessary  pressure  to  the  work  held  between  D  and  B  when 
the  blanks  are  being  drawn,  to  prevent  wrinkling. 

215 


216 


PUNCHES  AND  DIES 


II 


FIG.  286.  —  Section  through  combination  die 


FIG.  287.  —  The  forming  dies 


COMBINATION  AND  COMPOUND  DIES 


217 


The  blanking  die,  the  pressure  ring,  and  the  blanking  punch  are  of  tool 
steel,  hardened.  The  knock  out  pin  /  which  also  indents  the  top  of  the 
cover  is  likewise  of  tool  steel.  The  punch  holder  and  die  shoe  are  cast 
iron.  The  pressure  pins  E  are  drill  rod.  The  plates  or  washers  for  con- 
fining the  pressure  spring  are  of  machine  steel. 

The  forming  of  the  flange  around  the  edge  is  attended  to  in  the  second 
operation  dies,  Fig.  287.  A  detail  of  the  die  arrangement  is  seen  in  the 
partial  section,  Fig.  288.  Here  the  central  member  J  of  the  lower  die  is 
adapted  to  be  lifted  by  the  pressure  pins  K  to 
eject  the  work  after  the  punch  has  started 
upward. 


Upper  Die 


Pressure 
Pins~ 

FIG.  288.  —  Partial  view  of 
forming  die 


PRESSURE  SPRINGS  AND  PINS 

The  number  of  pressure  pins  used  about 
a  die  of  the  combination  type  varies  with 
the  size  and  form  of  the  work.  It  may  be  The 
that  three  will  answer  and  it  may  be  neces- 
sary to  use  four  or  more.  The  pressure  de- 
vice under  the  die  shoe  is  equipped  with 
the  weight  of  spring  necessary  for  accom- 
plishing the  work  of  controlling  the  pressure 
pad  to  give  the  desired  tension  to  .the  mate- 
rial being  drawn.  In  some  instances  the 
spring  used  must  be  of  very  heavy  section. 
Rubber  is  often  used  instead  of  a  coiled  spring  for  this  purpose,  and  some 
shops  use  it  almost  exclusively. 

Where  many  dies  of  this  order  are  in  service  it  is  customary  to  make  up 
a  number  of  these  pressure  devices  and  have  them  used  interchangeably 
throughout  a  series  of  dies  where  fairly  uniform  conditions  exist  as  to 
pressures  required.  Both  the  coiled  spring  and  the  rubber  buffer  types 
admit  of  considerable  variation  in  the  degree  of*  pressure  they  transmit, 
through  the  medium  of  the  adjustment  possible  by  the  nut  on  the  threaded 
supporting  stud.  But  often  the  range  of  work  is  such  that  a  wide  differ- 
ence is  required  in  the  drawing  pressures  for  different  dies  and  several 
spring  attachments  with  corresponding  range  in  their  working  capacities 
are  desirable,  if  not  absolutely  necessary. 

A  TAPER  SHELL  OPERATION 

In  Fig.  289  a  tapered  steel  shell  is  shown  which  is  made  in  three  oper- 
ations. The  first  is  in  the  combination  die,  Fig.  290.  Here  the  blank  is 
cut  and  drawn  to  the  cylindrical  form  shown  in  the  detail  with  dimensions 
of  2J  in.  diameter  by  1J  in.  deep.  The  blanking  die  is  at  A,  the  blanking 
punch  at  B.  The  metal  is  held  by  spring  pressure  between  the  upper 


218 


PUNCHES  AND  DIES 


face  of  spring  drawing  ring  or  pressure  pad  C  and  the  lower  face  of  the 
drawing  die  at  D,  while  the  cup  is  drawn  down  over  the  drawing  post  E. 
The  spring  F  is  adjusted  by  the  nut  below  to  put  sufficient  tension  on 
the  blank  so  that  it  will  not  wrinkle  as  it  is  pulled  down  from  between 


Dia. 

The  Finished  Cup 
(To  Larger  Scale) 

FIG.  289 


3rd  Operation 
Trim  Flange 

FIG. 293 
FIGS.  289-293.  —  Dies  for  drawing  and  trimming  taper  shell 


FIG.  292.  —  Dies  for  drawing  a  taper  shell 

faces  C  and  D.  On  the  upstroke,  the  ring  C  strips  the  work  from  the 
drawing  post  E  and  the  knock  out  G  clears  the  drawing  die  D.  The 
pressure  of  the  spring  F  is,  of  course,  transmitted  to  the  drawing  ring  C 
by  the  pins  H. 


COMBINATION  AND  COMPOUND  DIES 


219 


The  die  and  punch  are  of  tool  steel  hardened,  and  the  pressure  pins  are 
of  drill  rod.  The  die  shoe  is  cast  iron  and  the  punch  holder  is  a  machine 
steel  plate. 


FIG.  294.  —  Tools  for  making  a  small  bell 


FIG.  295.  —  Tools  for  making  a  small  bell 

The  second  operation  tools  for  tapering  the  shell  are  shown  in  Figs. 
291  and  292.  In  the  latter  view  a  shell  tapered  to  form  is  seen  in  the  fore- 
ground. These  tools  require  little  explanation.  The  knock  out  in  this 
case  is  in  the  bottom  of  the  die  and  its  head  forms  the  lower  portion  of  the 


220 


PUNCHES  AND   DIES 


die  proper.  This  set  of  tapering  tools  produces  a  flange  that  is  about  T^ 
in.  larger  than  required,  leaving  ample  stock  for  trimming  in  the  dies  in 
Fig.  293.  These  latter  dies  are  simply  a  piloted  punch  L  to  center  the  work 
and  an  open  die  M  to  trim  the  size  desired  for  the  flange.  The  trimming 
edge  of  the  punch  at  N  is  given  less  clearance  for  the  corresponding  edge 

of  the  die  than  would  be  allowed  for  a  blanking 
punch  of  the  same  diameter,  on  this  thickness  of 
stock,  to  prevent  possibility  of  the  narrow  edge 
of  the  flange  dragging  into  the  die. 


TOOLS  FOR  A  HEMISPHERICAL  CUP 


r.42  Hole 


Finish  to  .020  Edge 


Bell  l/s2  German  Silver 

FIG.  296.  —Detail  of  bell 


The  tools  in  Figs.  294  and  295  are  for  blank- 
ing and  drawing  up  the  german  silver  bell  seen 
in  detail  in  Fig.  296.  This  is  f  in.  outside  di- 
ameter and  has  a  slightly  flattened  top.  It  is  made  of  stock  -fa  in.  thick. 
The  two  photographic  views  have  been  included  to  show  more  clearly 

the   special   slide   for   carrying 

the    blank   material    into    the 

dies.     These  bells  are  blanked 

out  of  slugs  punched  out  in  a 

piercing    operation    in    making 

another  larger  piece.     They  are 

therefore  fed  into  this  die  by  a 

hand-operated    slide   having   a 


nest  the  size  of  the  slug  and  a 
definite  travel  back  and  forth 
to  receive  the  slug  conveniently 
and  when  pushed  forward  to 
center  it  over  the  die.  The 
central  position  of  the  slide  is 
ehown  by  Fig.  295;  the  preced- 
ing photograph  shows  the  slide 
withdrawn  for  another  piece  of 
blank  material. 

The  slugs  from  which  the 
bells  are  blanked  in  these  dies 
are  enough  larger  than  the 
blanking  punch  to  leave  a  fair 
margin  to  prevent  the  rim  of 
material  dragging  into  the  drawing  die.  The  stripper  over  the  slide  and 
stock  is  beveled  out  for  a  half  inch  in  all  directions  and  the  pressure  pad  or 
drawing  ring  comes  flush  with  the  cutting  edge  of  the  blanking  die  when  the 
punch  is  up.  The  general  features  of  the  tools  are  well  shown  by  the  photo- 


FIG.  297.  —  Construction  of  bell  tools 


COMBINATION  AND  COMPOUND  DIES  221 

graphs  and  the  sectional  drawing,  Fig.  297,  and  aside  from  the  foregoing 
reference  to  the  method  of  carrying  the  work  into  the  dies  little  descrip- 
tion seems  necessary. 

MAKING  A  SHALLOW  CIRCULAR  HOUSING 

The  press  tools  in  Fig.  298  are  for  making  a  circular  case  which  is  used 
as  a  pawl  housing  on  a  coin  register.  The  detail  of  the  piece  is  shown  by 
the  sketch,  Fig.  299.  From  this  latter  view  it  will  be  gathered  that  the 
shallow  case  or  housing  is  made  of  ^Vin.  soft  steel  which  is  drawn  up  to  a 
cup  ^52  m-  deep  inside,  the  outside  diameter  being  2f\  in.  The  blanking 
and  drawing  are  accomplished  in  the  combination  tools,  Fig.  300;  the 
piercing  of  four  holes  seen  in  the  detail  is  done  in  a  second  operation  with 
the  tools  sectioned  in  Fig.  301. 

The  different  elements  of  the  dies,  Fig.  300,  that  is,  the  cutting  edge 
for  the  blank,  the  blanking  punch,  the  drawing  post,  the  pressure  ring,  the 
knock  out  for  the  punch,  are  all  designated  by  name.  All  are  of  tool  steel 
hardened.  The  pressure  pins  and  pressure  spring  underneath  are  also 
indicated  by  their  respective  names  and  the  entire  construction  will  be  clear 
upon  inspection  of  the  sectional  view. 

Owing  to  the  fact  that  the  shell  is  very  shallow  in  proportion  to  the 
diameter  and  the  thickness  of  the  stock,  the  cutting  punch  is  necessarily 
quite  thin  in  its  side  walls,  and  for  that  reason  it  is  made  relatively  short  in- 
side to  give  as  much  strength  as  possible.  Inside  this  punch  is  carried  the 
upper  knock  out  which  has  a  positive  action  upon  striking  the  fixed  stop 
on  the  press  guides.  The  lower  ejector  is  the  same  pressure  ring  that  holds 
the  material  to  the  face  of  the  drawing  die  to  prevent  wrinkling  when  the 
latter  descends  over  the  drawing  post  in  the  lower  die. 

This  set  of  tools  like  the  second  operation  set  is  fitted  with  guide  pins 
similarly  to  the  bell  tools  in  preceding  illustrations. 

The  second  operation  tools,  Fig.  301,  pierce  the  central  hole  in  the  cup 
and  also  three  other  smaller  holes  spaced  from  the  center  in  accordance 
with  the  detail,  Fig.  299.  The  piercing  tools  are  fitted  with  a  steel  plate 
for  the  four  punches  as  indicated  and  the  punch  holder  carries  a  knock 
out  device  for  operating  the  stripper  which  is  made  a  close  fit  for  the  several 
piercing  punches.  The  die  is  recessed  out  to  give  a  depth  of  i  in.  for  the 
die  top.  The  work  locates  over  the  top  of  the  die  which  is  ground  to  2  in. 
diameter  to  suit  the  inside  of  the  drawn  piece. 

The  gap  at  one  side  of  the  work  is  cut  out  afterward  in  a  milling  operation. 

PIERCING  TOOLS  COMBINED  WITH  BLANKING  AND  DRAWING  DIES 
Oftentimes  the  operation  of  piercing  is  combined  in  tools  of  this  class 
with  the  blanking  and  drawing  or  forming  of  the  piece     A  case  of  this  kind 
is  illustrated  by  Fig.  302,  where  a  ^Vm-  cap  is  shown  as  drawn  and  pierced 
with  the  tools  in  Fig.  303. 


222 


PUNCHES  AND   DIES 


FIG.  298.  —  Tools  for  a  shallow  housing 


FINISHED  WORK  AFTER~MILLlNG 

.Fie.  299 


FiQ.-30'O 
FIGS.  299-300.  —  Dies  for  first  operation  on  pawl  housing 


COMBINATION  AND   COMPOUND  DIES 


223 


The  cap  is  2f  in.  inside  diameter  and  f  in.  deep.  It  is  a  gear  shifting 
lever  tower  cap  for  automobiles,  and  has  three  small  holes  spaced  near  the 
rim  and  a  larger  hole  through  the  center.  The  dies  blank,  draw,  and 
pierce  in  a  single  action  press. 


Positive 
Knock-out 


FIG.  301.  —  The  piercing  tools 

The  die  is  constructed  as  follows :  The  blanking  and  forming  punch  A 
which  is  of  tool  steel,  hardened  and  ground,  is  fastened  to  the  cast  iron 
punch  holder  B.  The  blanking  die  C  is  of  tool  steel  hardened  and  ground 
and  seated  in  the  cast  iron  base  D.  The  piercing  and  forming  die  F  is 
also  seated  in  the  base.  The  piercing  punches  G  are  shouldered  to  resist 
the  force  required  for  piercing,  and  are  held  in  place  by  headless  set  screws. 
The  stripper  H,  which  strips  the  scrap  from  the  blanking  punch,  is  sus- 
pended from  the  punch  holder  by  six  special  screws  I,  which  also  serve  as 
retainers  for  the  stripper  springs. 

A  rule  that  has  been  used  successfully  for  the  calculation  of  the  strip- 
ping pressure  required  is  to  take  this  at  approximately  7  per  cent  of  the 
blanking  pressure.  The  upper  knock  out  K  is  held  in  alinement  with  the 
punches  by  the  three  pins  L,  abutting  against  the  disk  Q,  which  transmits 
the  spring  pressure  from  the  three  springs  R  to  the  blank  holder.  The 


224 


PUNCHES  AND  DIES 


spring  tension  is  adjusted  by  the  nuts  S.  The  guide  pins  T,  which  are  of 
different  diameters  to  prevent  missetting  of  the  die,  are  a  press  fit  in  the 
base  and  a  sliding  fit  in  the  punch  holder.  The  shank  U  is  fastened  in  the 
ram  of  the  press. 


FIG.  302  FIG.  303 

FIGS.  302-303.  —  The  cap  and  details  of  the  die 

The  operation  of  the  die  is  as  follows:  The  blank  is  cut  from  the  strip 
by  the  punch  A  at  the  point  marked  V,  and  is  held  under  tension  between 
the  punch  A  and  the  blank  holder  0.  The  punch  A  continues  down,  form- 
ing the  cup  around  the  die  F.  The  punches  G  then  pierce  the  holes; 
the  knockout  K  serves  as  a  bumper,  flattening  the  face  of  the  cap.  On  the 
return  stroke,  the  scrap  is  stripped  from  the  punch  A  by  the  stripper  H.. 
The  cup  is  pushed  up  flush  with  the  blanking  surface  V  by  the  stripper  0. 
The  knockout  K  ejects  the  cap  from  the  punch.  It  is  essential  to  secure 
an  even  edge  on  the  cap.  No  trimming  is  required  with  this  type  of  die. 


COMBINATION  AND  COMPOUND  DIES 


225 


DIES  FOR  A  VALVE  SPRING  CUP 

The  cup  in  Fig.  304  is  formed  with  a  channel  around  the  base  of  the 
flange  and  a  ||-hole  is  pierced  through  the  center  of  the  piece. 

In  the  construction  of  the  dies  for  this  work,  see  Fig.  305,  the  blanking 
and  forming  ring  A,  is  seated  in  a  base  B;  the  blanking  punch  C  which 
serves  as  a  guide  for  the  form- 
ing punch  D  is  fastened  to  a 
cast  iron  holder  E.  The  part 
F  strips  the  scrap  from  the 
punch.  The  knockout  G  is 
supported  by  four  push  pins 
H  abutting  against  the  washer 
J,  which  serves  as  a  retainer 
for  the  spring  K,  the  tension 
of  which  is  regulated  by  ad- 
justment of  nut  L.  The  stud 
M  which  supports  the  knock- 
out arrangement  is  drilled 
through  to  allow  the  scrap 
punchings  or  slugs  to  escape. 
Slots  are  cut  in  the  top  face 


FIG,  304.  —  The  spring  cup  to 
be  made 


FIG.  305.  —  The  combination  die  used 


of  the  punch  holder  to  prevent  the  entrapment  of  air  in  the  guide  pin 
bushings. 

In  operation,  the  blank  is  cut  from  the  strip  by  the  punch  C  and  forced 
down  to  the  draw  edge.  The  forming  punch  D  and  the  piercing  punch  N 
then  descend,  completing  the  cup.  As  the  press  ascends,  the  punch  D 
disappears  through  the  opening  of  the  blanking  punch  C,  stripping  the 
cup,  while  the  knockout  ejects  the  cup  from  the  die  ring. 

MUFFLER  CUP  TOOLS 

The  combination  blanking,  drawing,  forming,  and  piercing  die  in  Fig. 
306  is  used  in  a  single  acting  press  for  making  muffler  cups  for  automo- 


226 


PUNCHES  AND  DIES 


biles.     The  parts  are  all  designated  by  name  to  permit  of  easy  reference, 
and  a  brief  description  of  the  action  of  the  tools  will  suffice. 

When  the  blanking  punch  descends,  it  enters  the  blanking  die,  and  the 
blank  is  held  firmly  by  the  drawing  ring  against  the  bottom  of  the  blanking 
punch  to  prevent  wrinkling.  As  the  downward  movement  continues,  the 


^'Pressure 
fin 

FIG.  306.  —  Blanking,  drawing,  forming,  and  piercing  die 

blank  is  drawn  between  the  bore  of  the  blanking  punch  and  the  drawing 
punch.  As  it  reaches  the  end  of  the  stroke,  the  rim  is  formed  between  the 
shoulder  in  the  blanking  punch  and  the  tapered  shoulder  on  the  drawing 


Plan 


FIG.  307.  —  Brass  coupling,  No.  20  gage 

punch.  The  holes  are  pierced  by  punches  located  in  the  punch  block  and 
the  dies  in  the  base  below.  A  spring  stripper  is  used  as  represented.  The 
knock  out  is  kept  in  line  with  the  piercing  punches  by  a  Whitney  key. 

SET  OF  TOOLS  FOR  A  BRASS  COUPLING 

The  pressed  brass  coupling  in  Fig.  307  is  drawn  in  two  operations. 
The  first  operation  A  consists  in  blanking  and  drawing  from  a  4f-in.  blank 
in  the  dies  shown  in  Fig.  308.  These  tools  are  set  up  in  a  single  action 


COMBINATION   AND  COMPOUND  DIES 


227 


press  and  the  shell  must  be  drawn  to  a  developed  depth  in  order  to  corre- 
spond properly  with  the  next  operation  dies  so  as  to  give  the  desired  results. 
In  setting  up  this  die,  care  must  be  exercised  in  adjusting  the  rubber 
buffer  N.  Too  much  stress  on  the  pressure  pad  F  would  strain,  stretch, 
and  possibly  break  the  brass,  while  not  enough  stress  on  the  pressure  pad 
would  permit  the  metal  to  wrinkle  and  cause  breakage  and  poor  work 


FIG.  308  FIG.  309 

FIGS.  308-309.  —  Dies  for  a  pressed  brass  coupling 

in  the  operation  that  follows.  The  lower  punch  E  in  the  die  has  a  small 
vent  to  facilitate  the  removal  of  the  work  from  the  punch  and  prevent  dis- 
tortion. 

The  blanking  punch  A  has  a  positive  knockout  that  comes  in  contact 
with  the  stationary  knockout  bar  attached  to  the  press  while  in  operation. 
Should  the  shell  stay  in  the  punch,  it  is  easily  released  on  the  upward  stroke. 
The  compound  blanking  and  cupping  punch  A  is  made  of  machinery  steel 
with  a  tool  steel  bushing  B  pressed  into  place  and  secured  by  screws  C. 
The  bushing  B  which  does  the  actual  work  of  blanking  and  cupping  can  be 
shrunk  several  times  when  it  wears  large  and  is  easily  replaced  with  a  new 
one  when  this  becomes  necessary.  A  punch  of  this  type,  when  its  diameter 
exceeds  4  in.,  is  cheaper  and  has  a  longer  life  than  a  solid  tool  steel  punch, 
because  the  bushings  can  be  shrunk  to  size  so  often. 

The  blanking  punch  D,  the  forming  punch  E,  and  the  pressure  pad  F 
are  made  of  tool  steel,  hardened  and  ground  to  size.  The  forming  punch 
E  is  held  in  position  by  the  bolt  H,  which  has  a  vent  similar  to  that  in  the 
punch  E.  The  outlet  is  at  X.  The  blanking  die  has  TV  in.  shear  and  is 
held  in  position  by  machine  steel  strippers  7,  in  turn  held  in  place  by  cap 
screws  J  and  dowel  pins  K  seated  and  screwed  to  the  cast  iron  die  plate  L. 
The  latter  is  secured  to  the  bolster  plate  by  cap  screws  0.  The  pressure 


228  PUNCHES  AND   DIES 

pad  pins  M  are  made  of  hardened  and  ground  tool  steel  and  transmit  the 
pressure  to  the  pad  F  from  the  rubber  buffer  N,  which  is  adjusted  by  the 
lock  nuts  P. 

The  second  operation,  indicated  at  B,  Fig.  307,  is  performed  in  the 
drawing*  and  perforating  dies  shown  in  Fig.  309.  These  dies  draw  the 
tap.ered  shell  B  with  a  flange  concentric  with  the  walls  of  the  shell,  perforate 
four  rivet  holes  in  the  flange,  and  punch  out  the  bottom  simultaneously. 
Thus  the  coupling  is  finished  in  two  operations.  By  using  a  die  of  this 
type,  trimming  is  unnecessary,  so  that  it  is  possible  to  use  a  smaller  blank, 
thereby  saving  valuable  stock  and  completing  the  article  in  the  briefest 
possible  manner. 

The  drawing  punch  A,  of  tool  steel,  hardened,  has  double  stripper 
bushings  BC,  made  of  tool  steel,  hardened  and  ground.  The  bushing  C, 
connected  with  the  bushing  B  by  springs  and  screws  G  is  screwed  and  pinned 


FIG.  310.  —  Dies  for  a  brass  bushing 

to  the  machine  steel  stripper  bar  D,  which  is  held  in  place  on  the  punch 
by  the  bolts  E  screwed  to  the  ram  of  the  press.  When  these  bolts  are 
properly  adjusted,  they  give  the  correct  sliding  motion  on  the  punch  to 
release  the  stamping  during  the  last  J  in.  of  the  upward  travel  of  the 
press  ram. 

It  is  obvious  that  when  the  punch  descends  and  enters  the  shell  X  the 
plug  H  (of  tool  steel,  hardened  and  ground),  having  the  proper  spring  ten- 
sion will  straighten  the  shell  in  the  bushing  C.  This  tension  from  thte 
spring  S  causes  the  bushing  C  to  close  on  the  die  on  the  last  J  in.  of  travel 
of  the  punch,  which  is  necessary  in  order  that  the  surplus  flange  stock  may 
be  properly  forced  into  the  die  and  down  along  the  sides  of  the  draw  punch, 
assisting  the  drawing  and  perforating  the  flange  notes. 

The  punch  A  is  straight  for  -^  in.  above  the  curve  on  the  Icrwer  end  to 
allow  for  the  necessary  over  travel  to  upset  the  end  of  the  coupling  slightly 
and  prevent  it  from  having  a  feather  edge.  The  perforating  punches  / 
are  made  of  tool  steel  hardened  and  ground,  and  screwed  into  place  by 
having  their  heads  threaded  and  slotted.  The  perforating  punches  J 


COMBINATION  AND  COMPOUND  DIES 


229 


are  made  of  tool  steel,  hardened,  ground,  and  pressed  into  place.  The 
bashing  K  is  likewise  of  tool  steel,  hardened  and  ground.  It  is  held  in 
place  by  the  drawing  die  L,  which  is  seated  in  the  cast  iron  die  plate  M  and 
secured  by  the  screws  0.  The  die  plate  is  fastened  to  the  press  bed  by  cap 
screws  X. 

A  BRASS  BUSHING  OUTFIT 

The  brass  bushing  at  the  extreme  left  of  the  parts  in  the  foreground  of 
Fig.  310  is  blanked,  drawn,  and  pierced  by  the  tools  at  the  right  in  the  same 
photograph,  and  is  then  trimmed  in  the  other  dies  at  the  left  in  the  same 
engraving.  A  detail  of  the  bushing  is  shown  in  the  drawing,  Fig.  311. 
The  first  operation  tools  are  shown  complete  in  the  drawing,  Fig.  312, 
and  all  details  are  included. 

Referring  to  this  drawing,  the  cutting  edge  of  the  blanking  die  is  shown 
at  A,  and  inside  of  this  die  is  the  compound  drawing  plug  and  ring  B  with 


FIG.  311.  —  The  brass  bushing  finisjied 

the  friction  ring  or  pressure  ring  C  filling  the  annular  space  between.  The 
drawing  plug  B  rests  upon  pressure  pins  D  and  the  ring  C  upon  longer 
pressure  pins  E  which  pass  down  through  holes  in  the  base  of  plug  B  and 
abut  upon  pressure  plate  F  which  acts  uniformly  upon  both  sets  of  pins 
D  and  E.  Plate  F  is  controlled  by  the  rubber  buffer  or  spring  G  which  is 
secured  between  F  and  a  lower  plate  H,  the  latter  being  adjusted  by 
the  nut  on  the  supporting  length  of  tubing  to  allow  the  rubber  to  apply 
any  desired  degree  of  pressure  to  the  friction  ring  and  plug  B  above. 

The  blanking  punch  7  is  bored  out  and  ground  to  1.560  in.  to  form  the 
drawing  die  inside  for  the  larger  diameter  of  the  work  and  in  this  is  fitted 
the  die  J  which  draws  up  the  smaller  diameter  at  the  end  of  the  work. 
The  latter  die  is  adapted  to  slide  upward  for  a  distance  of  ^f  in.  and  upon 
the  upstroke  of  the  punch  it  is  forced  downward  to  flush  position  by  the 
pins  K  and  the  knockout  plug  L  above.  In  the  center  of  the  punch  holder 
is  pressed  snugly  the  piercing  punch  M  which  may  be  adjusted  for  depth 


230 


PUNCHES  AND   DIES 


of  position  by  the  screw  N.  The  die  J  is  stopped  for  lower  position  by  the 
ring  0  which  encircles  the  blanking  punch  and  which  carries  three  screws 
passing  through  vertical  slots  in  the  punch  wall  and  entering  holes  in 
the  die  J. 

The  piercing  die  is  located  at  P  in  a  seat  bored  in  the  die  shoe  or  base 
and  is  relieved  from  the  lower  end  to  give  a  cutting  length  at  the  top  of 
only  about  J  in.  as  shown  by  the  detail  at  P. 


1-Friotion  Ring  Tool  Steel 
Harden  &  Grind 


Compound  Drawing  Plug  &  Uing 

Tool  Steel  Harden 

Maker.l 


Locate  Hight  of  Piercing 
Punch  by  Trial 


Close  Fitting  Hug/16 
Harden  and  Draw  to  iMue 

Me  - 


T-  fc-         uxiic.  y_  _w      \& 
Make  3  M.S.  CfflT   .. 


Press  Fit  in  Casting 

Center  Plug  &  Piercing  Die 

Tool  Steel  Harden 

Make-1 


10  5  Open      ound 

.025  Muaic  TO«.     ' 


T.S.  Harden  and  Temper 
Press  Fit  in  Punch 

FIG.  312.  —  Details  of  combination  blanking  and  drawing  dies 

The  dies  are  seen  in  Fig.  313  as  they  appear  with  the  work  in  place  and 
drawn  to  shape  for  the  two  diameters  and  the  hole  pierced  through  the  end. 
The  same  letters  are  here  used  for  reference  as  in  the  other  drawing  just 
referred  to.  The  top  surfaces  of  spring  controlled  members  B  and  C  act  as 
friction  surfaces  or  pressure  rings  to  allow  the  two  sizes  of  draws  to  be  made 
without  wrinkling  of  the  metal.  When  the  punch  holder  (which  is  made 
in  one  piece  with  the  blanking  punch  7)  rises,  the  knock  out  K  and  ring  0 
are  actuated  to  eject  the  work  from  the  upper  dies.  The  scrap  is  stripped 
from  the  blanking  punch  by  open  stripper  plates  attached  to  the  lower  die 
face  as  shown  in  the  photographic  view,  Fig.  310. 


COMBINATION  AND  COMPOUND  DIES 


231 


THE  SECOND  OPERATION  DIES 

The  trimming  dies  are  illustrated  by  Fig.  314  and  Fig.  315  shows  the 
work  in  place  and  ready  for  the  trimming  of  the  edge  in  die  Q.  This  die  (refer 
to  both  drawings)  in  conjunction  with  punch  R  trims  the  edge  of  the  shell 
to  1.782  in.  diameter.  This  leaves  a  small  amount  of  stock  which  is  fin- 


FIG.  313.  —  Blanking  and  drawing  dies  in  operation 

ished  to  a  perfect  beveled  edge  in  a  later  operation  in  a  screw  machine  where 
the  inside  of  the  shell  is  turned  out  to  a  positive  diameter  and  the  end  faced 
exactly  to  length,  in  accordance  with  the  drawing  of  the  finished  piece  in 
Fig.  311. 

Referring  again  to  Figs.  314  and  315,  the  work  is  centered  by  the 
piloted  punch  S  screwed  into  the  punch  holder.  This  holder  like  the 
other  is  of  tool  steel  and  its  lower  end  is  finished  by  turning  and  grinding 
to  form  the  holder  for  the  work.  This  portion  of  the  punch  also  carries 
the  combined  trimming  punch  and  stripper  T  which  is  connected  with 


232 


PUNCHES  AND  DIES 


the  cross  plate  U  which  in  turn  is  connected  with  the  lower  die  base  by  two 
sliding  bolts  V  which  prevent  the  stripper  from  rising  beyond  a  certain 
point  on  the  upstroke  of  the  press  ram. 

On  the  down  stroke,  the  locating  punch  S  and  the  punch  holder  descend, 
as  in  Fig.  315,  until  the  work  is  secured  against  the  face  of  the  trimming  die 


Note:   „  .  -*- 

B  +.457-=  A  -When  Grinding  f o\ 
tiis  Porportiou  must  be  Mai 


Harden  &  Grind  all  T.  8,  Parts  . 

Use  M"CoU' Spring 


Trimming  Punch  &  Stripper 
Make-liT.S.  Harden  &  Grind. 


FIG.  314.  — •  Construction  of  trimming  dies 

pressure  pad  W,  the  top  of  the  stripper  plate  U  is  then  against  the  lower 
face  of  the  punch  holder  shoulder  X  and  the  trimming  punch  R  must  then 
travel  downward  with  the  rest  of  the  upper  tools.  The  pressure  ring  W  is 
forced  down  against  the  spring  pressure  transmitted  by  pins  Y  and  the 
work  is  held  securely  while  being  pushed  into  the  trimming  die  Q. 

On  the  upstroke  of  the  ram,  the  pressure  ring  W  carries  the  work  out  of 
the  trimming  die  Q  and  when  the  stripper  plate  U  reaches  its  limit  of  travel 
upward,  as  determined  by  the  stop  bolts  V,  the  punch  holder  continuing 
upward,  causes  the  ring  and  stripper  R  to  strip  the  work  from  the  punch. 
The  stripper  ring  is  provided,  as  shown  in  Fig.  314,  with  two  wedge  shaped 
points  at  the  sides  to  split  the  thin  ring  of  scrap  trimmed  off  from  the  work 
as  it  accumulates  on  the  surface  of  the  punch  and  thus  keep  the  punch 
clear. 

It  is  evident  that  dies  of- this  class  must  be  set  up  in  the  press  with  some 


COMBINATION  AND  COMPOUND  DIES 


233 


care  to  effect  the  desired  results.  Particularly  with  the  first  operation  dies 
which  draw  two  different  diameters,  judgment  must  be  used  to  adjust  the 
different  elements  properly  to  assure  the  correct  distribution  of  metal 
between  the  two  sizes  drawn  on  the  one  shell.  To  facilitate  the  setting 
operation  the  set  of  standard  pieces  or  models  shown  in  the  foreground  of 


FIG.  315.  —  Trimming  die  in  operation 

Fig.  310  are  kept  available.  These  pieces  are  made  up  to  represent  cor- 
rect heights  and  sizes  of  draw  for  the  shell  for  every  sixteenth  inch  of  move- 
ment on  the  part  of  the  press  tools.  Thus,  when  the  tools  are  being  set, 
the  operator  can  draw  a  blank  to  the  first  sixteenth  of  depth  and  compare 
results  with  the  model  parts  used  for  comparison  gages,  and  so  on  with  the 
setting  adjustments  until  each  advance  of  the  amount  specified,  or  .^V  in., 
produces  a  partially  drawn  shell  corresponding  in  all  dimensions  with  the 
models,  or  masters  shown,  and  the  completed  trial  piece  becomes  a  dupli- 
cate of  the  full  drawn  model. 


234 


PUNCHES  AND  DIES 


DRAWING  FINE  WIRE  MESH 

One  more  example  of  a  set  of  blanking  and  drawing  tools  will  be  shown 
in  this  chapter.  The  tools  in  Fig.  316  are  for  an  unusual  piece  of  work,  a 
fine  meshed  copper  wire  screen  for  a  carburetor.  This  would  appear  to  be 
difficult  material  to  work  in  the  press,  but  with  the  tools  illustrated  no 
trouble  whatever  has  been  encountered. 

The  wire  screen  is  shown  in  Fig.  317  somewhat  more  clearly  than  in  the 
view  of  the  dies.  The  dimensions  are  given  in  the  sketch,  Fig.  318,  which 


FIG.  316.  — •  Tools  for  a  fine  mesh  screen  for  a  carburetor 


TIG.  317.  —  The  small  screens  as  they  appear  when  fitted  with  center  ring 

shows  a  vertical  section  through  the  dies.     The  wire  screen  is  drawn  up 
to  a  diameter  of  If  in.  and  to  a  depth  of  about  f  in. 

The  tools  are  so  made  that  although  they  blank  and  form  and  pierce 
in  one  operation,  the  drawing  operation,  or  forming,  is  accomplished  first, 
the  wire  being  pressed  down  into  the  spherical  seat  in  the  pressure  pad  A 
and  held  there  by  the  punch  B  and  the  action  of  the  pressure  pins  C  and 
the  rubber  buffer  D  below,  while  the  blanking  is  done  with  the  cutting 
edge  of  the  punch  and  the  blanking  die  E.  At  the  same  time  the  piercing 
punch  F  pierces  the  hole  through  the  center,  the  piercing  die  being  formed 
at  G  in  the  center  of  the  punch  B. 


COMBINATION  AND   COMPOUND   DIES 


235 


The  stripper  is  carried  at  H  on  three  small  screws  with  springs  between 
stripper  and  punch  holder,  J.  As  the  work  leaves  the  dies  it  tends  to 
spring  back  to  an  approximately  flat  form,  as  seen  in  Fig.  317,  and  itjwlll 


4-Sided  Effect 
on  .Blank  as  it  comes 


FIG.  318.  —  Construction  of  tools  for  screen 

be  noticed  that  the  outline  of  the  screen  is  four  sided  with  slightly  rounded 
edges  but  otherwise  closely  resembling  a  square  piece.  When  assembled 
in  the  carburetor  it  is  placed  in  a  circular  seat  and  there  retains  its  hemi- 
spherical form.  The  brass  eyelet  shown  at  the  center  is,  of  course,  set 
into  place  in  a  subsequent  operation. 


CHAPTER  X 


BENDING  AND   FORMING  TOOLS 

Bending  dies  in  their  simplest  form  consist  of  a  plain,  open  set  of  tools, 
like  those  in  Fig.  319,  which  are  illustrated  as  used  for  bending  up  a  slender 
steel  part  which  forms  a  bell  tapper  arm  for  a  calculating  machine.  The 
piece  itself  is  shown  by  Fig.  320  as  it  appears  when  attached  to  the  tapper. 
It  is  made  of  half  hard  steel  0.050  in.  thick  and  the  blanking  dies  for  pro- 
ducing it  are  shown  in  Fig.  40,  Chapter  II. 

The  bending  dies,  Fig.  319,  are  provided  with  a  locating  nest  at  the  top 
of  the  bending  V  in  which  the  head  of  the  blank  is  seated,  while  the  long 


FIG.  319.  —  A  plain  bending  die 

arm  is  slipped  between  two  guide  pins  in  front  of  the  V-block.  The  punch 
is  formed  with  a  similar  V  and  one  stroke  of  the  press  forms  the  straight 
blank  into  the  piece  with  two  right  angle  bends  so  that  the  projecting  arm 
is  thrown  again  parallel  to,  but  offset  from,  the  clover  shaped  head.  These 
tools,  like  many  similar  dies,  are  used  in  a  foot  press. 

The  die  base  is  a  cast  iron  member,  and  the  die  proper  is  of  tool  steel 
hardened.  The  punch  or  upper  die  is  also  of  tool  steel  hardened.  The 
work  before  and  after  bending  is  seen  in  the  foreground  of  the  photographic 
view. 

236 


BENDING  AND  FORMING  TOOLS 


237 


USE  OF  THE  SPRING  PAD  OR  KNOCKOUT 

The  dies  shown  require  no  pressure  pad  or  knockout,  owing  to  the  form 
and  proportions  of  the  work.  There  are  many  instances,  however,  where 
even  the  simplest  pieces  are  bent  with  greater  convenience  by  the  addition 
of  a  knockout  to  the  dies 
and  in  many  other  in- 
stances the  knockout  or 
some  other  form  of  spring 
actuated  device  is  abso- 
lutely necessary.  This  is 
also  essential  for  locating 
and  holding  the  blank  in 
many  cases. 

A  simple  piece  of  bend- 
ing work  with  a  spring  pad 
in  the  dies  is  shown  by  Fig. 
321.  The  work  is  a  TVin. 
steel  rod  with  one  end  bent 


.640  Music  Wire   2%    Long 
Soldered  to  Arm. 


x  V*  Slug  Soldered 
to  Wire 


42  Drill 


Apprcx,  Length  of  Arm  2.H 

FIG.  320.  —  The  piece  bent  in  the  dies  Fig.  319 


up  to  a  length  of  J|  in.,  the  body  being  4T9#  in.  long.      The  dies  require  little 
description.     They  are  made  with  guide  pins  for  alinement  and  rigidity  and 


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The  Work 


FIG.  321.  —  Bending  dies  for  a  round  rod 

the  upper  and  lower  dies  proper  are  concaved  for  one-half  of  the  diameter 
of  the  rod  in  each  face.  The  pad  A  is  provided  with  a  similar  half  round 
groove  and  the  work  is  readily  located  by  slipping  it  into  this  concave  seat 
and  resting  its  inner  end  against  stop  shoulder  B.  On  the  down  stroke,  the 


238  PUNCHES  AND  DIES 

rod  is  forced  down  over  the  rounded  corner  of  lower  die  C  and  formed  to 
the  right  angle  bend  desired.  When  the  upper  die  ascends,  the  spring  pad 
A  lifts  the  work  clear  and  is  ready  for  another  blank.  The  dies  and  pad  are 
made  of  tool  steel  and  hardened. 

The  pressure  pins  D  are  actuated  by  a  spring  pressure  attachment  whose 
supporting  stud  screws  into  the  tapped  hole  in  the  lower  die  shoe  at  E. 
This  is  similar  to  the  usual  spring  attachment  used  with  various  classes 
of  dies  already  shown  in  this  book  and  need  not  be  detailed  here. 

BENDING  Two  EARS  ON  A  BLANK 

In  Fig.  322  (at  the  right)  are  a  pair  of  dies  for  bending  up  two  lugs  or 
ears  on  a  bracket  shaped  piece  shown  in  detail  in  Fig.  323.  This  is  pierced 
and  blanked  with  the  tools  at  the  left  in  Fig.  322,  the  form  of  the  blank 
being  clearly  represented  in  the  detail  sketches.  The  piece  is  made  from 


FIG.  322.  —  Blanking,  piercing,  and  forming  dies  for  a  small  bracket 

-/i  in.  steel,  and  has  two  J-in.  holes  pierced  in  the  end  which  are  later  used 
in  the  finished  work  for  receiving  a  rivet  or  pin  for  hinging  another  member 
between  the  bent  up  arms. 

The  two  pierced  holes  are  made  use  of  for  locating  the  blank  on  the 
bending  dies  shown  more  fully  in  Fig.  324.  The  die  proper  here  is  seen  at 
F  and  the  punch  or  upper  die  at  G.  Die  F  is  cut  out  midway  of  its  width 
to  receive  a  pressure  pad  and  ejector  H  which  is  formed  at  the  front  end  to 
give  the  downward  bend  to  the  lip  of  the  blank.  In  this  way  it  is  made  to 
form  part  of  the  die  itself  in  that  it  performs  a  portion  of  the  work  of  shaping 
the  piece  to  dimensions.  A  counterpart  of  the  bend,  but  in  the  reverse 
direction,  is  formed  on  the  end  of  the  punch  G.  The  latter  is  naturally 
less  in  width  than  the  opening  0  across  the  die  face  by  an  amount  equal  to 
twice  the  thickness  of  the  material.  As  with  drawing  dies  it  is  desirable 
to  give  the  corners  of  the  bending  dies  a  liberal  radius  to  enable  the  work 
to  pull  over  and  down  the  side  of  the  die  without  breaking  or  tearing.  This 
also  enables  the  bend  to  start  easily. 


BENDING  AND  FORMING  TOOLS 


239 


As  the  punch  comes  in  contact  with  the  blank,  the  projecting  ears  on  the 
blank  swing  upward  and  release  the  work  from  the  very  short  locating 
pins  /  and  the  punch  continuing  downward  presses  the  blank  down  be- 
tween the  die  jaws  and  forms  it  to  shape.  With  the  return  of  the  punch, 
the  spring  pad  F  carries  the  work  up  and  out  of  the  die. 


Fic.323 


BENT, AND  FORMED 


FIGS.  323-324.  —  Construction  of  bending  or  forming  die 

A  DOUBLE  BENDING  OUTFIT 

Where  simple  tools  are  preferred  it  is  often  necessary  to  use  two  or  more 
sets  of  bending  dies  for  performing  the  same  number  of  distinct  operations 
on  a  piece.  With  compound  bending  tools  parts  requiring  complicated 
bending  and  forming  operations  are  completed  in  one  setting. 


240 


PUNCHES  AND  DIES 


The  work  shown  in  Fig.  325  is  a  steel  bracket  ^  in.  thick  which  is 
blanked  and  pierced  in  the  tools,  Fig.  326,  where  the  blanking  operation 
consists  in  shearing  off  the  end  of  a  strip  of  the  right  width  and  piercing  the 
holes  at  the  same  stroke  of  the  press.  The  end  of  the  strip  rests  against 
stop  A  after  the  first  stroke  of  the  press  and  this  gives  the  right  position 
for  cutting  off  to  length  by  the  shearing  punch  B  and  the  cut-off  end  of 
the  die  C.  With  such  small  punches,  as  are  here  used,  it  is  desirable  to  have 
the  cut  off  punch  act  first  before  the  piercing  punches  enter  the  work,  thus 
preventing  the  latter  from  being  injured  or  broken.  The  strip  of  material 
rests  between  the  gage  studs  D  while  in  the  dies  and  the  four  gage  stops  thus 
hold  the  strip  central  and  square  during  the  operation.  Their  heads  also 
form  a  stripper. 


Wr/32'andCut-°ff 

1st  OP. 
FIG.  3  26 


2nd  Op. 
FlG.32.7 


3rd  Op. 
FlC.328 


FIG.  325 


FIGS.  325-328.  —  Dies  for  double  bending  operation 


The  first  bending  operation  consists  in  turning  up  the  ends  to  a  right 
angle  with  the  dies  in  Fig.  327.  Here  the  blank  is  placed  in  the  die  with 
the  ends  between  stop  surfaces  FF  which  form  a  locating  nest  while  the 
punch  descends  and  draws  the  work  down  between  the  bending  jaws 
GG.  The  knock  out  H  is  supported  by  two  pins  which  abut  upon  the 
spring  pressure  device  below,  and  when  the  punch  ascends,  the  spring 
pins  carry  the  work  up  for  removal  and  transfer  to  the  next  operation 
dies,  Fig.  328 

Here  the  work  rests  over  the  two  gage  pins  II  and  the  punch  in  descend- 
ing performs  the  second  bending  operation  by  forcing  the  middle  of  the 
bent  blank  down  between  die  jaws  KK,  where  the  body  of  the  piece  is 
formed  to  the  outline  indicated  in  the  sketch  of  the  third  operation.  The 
action  of  the  knock  out  is  the  same  as  with  the  one  in  the  first  operation  die 


BENDING  AND  FORMING  TOOLS 


241 


Fig.  327.  The  die  jaws,  punch,  and  strippers  here  are  of  tool  steel,  hard- 
ened, the  pressure  pins  of  drill  rod  hardened,  the  die  base  and  punch  holder 
are  machine  steel  plates  finished  to  1  in.  in  thickness. 

THE  PRESSURE  PAD  ON  TOP  OF  THE  WORK 

It  is  occasionally  the  case  that  the  die  is  designed  to  hold  the  work 
blank  on  top  of  the  anvil  or  flat  part  of  the  bending  die  by  means  of  a 
pressure  pad  while  the  punch  or  upper  die  is  engaged  in  bending  some  pro- 


T 


The  Pierced  Blank 


,093  S.S.  Steel 


.093 


The  Work  Bent  to  Shape 
FIG.  329 

jecting  portion  of  the  piece.  In  this  case  the  work  is  placed  in  some  form 
of  nest  or  located  over  gage  pins,  and  when  the  punch  descends,  the  pressure 
pad  holds  the  material  firmly  for  the  forming  of  the  bent  portion.  An 
example  is  illustrated  in  Fig.  329  which  is  a  sketch  of  a  small  bracket  for 
a  register  device,  where  the  round  end  is  bent  at  right  angles  to  the  body. 
The  piece  is  pierced  and  blanked  in  progressive  dies  in  an  earlier  opera- 
tion and  the  form  of  the  blank  is  shown  at  A.  The  shape  of  the  member 
after  bending  is  seen  at  B.  The  material  is  0.093  in.  soft  rolled  steel. 


242 


PUNCHES  AND   DIES 


The  bending  dies  are  shown  in  Fig.  330.  The  work  is  placed  over  the 
two  pins  in  the  face  of  the  die  block  C  and  is  held  squarely  by  these  pins  for 
the  application  of  the  bending  punch  D.  As  the  punch  holder  descends, 
the  pressure  pad  E  which  is  backed  up  by  a  very  stiff  spring,  is  forced  down 
upon  the  work  and  held  securely  during  the  folding  down  of  the  end  over 
the  edge  of  the  die.  When  the  punch  rises  again,  the  pressure  pad  follows 
it  and  the  work  is  released. 

Two  blanks  are  bent  at  once  in  these  dies.  This  means  a  wider  pressure 
pad  than  would  be  required  for  a  single  blank  and  the  proportions  of  the 
pad  are  therefore  made  such  that  two  springs  may  be  used  and  a  better 


FIG.  330.  —  Bending  dies  for  a  light  bracket 

balanced  action  is  thus  made  possible.  The  work  is  placed  and  removed 
as  readily  as  a  single  blank  would  be  and  there  is  a  great  advantage  in 
output  from  this  arrangement. 

The  desirability  of  the  guide  pins  for  the  punch  and  die  bases  is 
obvious  as  without  them  there  would  be  much  sacrificed  in  the  way  of 
rigidity  of  the  tools.  The  pressure  and  thrust  all  being  in  one  direction, 
there  would  be  more  or  less  difficulty  in  the  unsupported  dies  through 
tendency  toward  displacement  of  one  member  or  the  other  of  the  pair. 


BENDING  AND  FORMING  TOOLS  243 

As  with  other  dies  shown,  the  die  block  and  bending  punch  or  upper 
die  are  held  to  the  die  base  and  punch  plate  by  fillister  head  screws  and 
dowel  pins.  The  pressure  pad  is  carried  by  two  fillister  head  screws  whose 
heads  are  free  to  travel  in  the  counterbored  holes  in  the  punch  plate. 

KNOCK  OUT  FOR  BOTH  PUNCH  AND  DIE 

Fig.  331  illustrates  a  case  where  knockouts  are  applied  to  both  punch 
and  die  for  certain  operations  in  bending.  The  work  is  part  of  a  sheet 
metal  hinge  appearing  when  completed  as  shown  at  C.  The  blank  is  seen 
at  A  and  the  first  bending  operation  produces  an  article  illustrated  at  B. 
The  piece  is  made  of  0.0625  in.  sheet  steel,  1J  in.  wide. 

The  first  operation  tools,  Fig.  332,  pierce  the  six  holes  and  cut  off  the 
blank  from  the  strip  of  steel.  The  stock,  after  the  end  has  been  trimmed  off, 
is  fed  to  the  stop  E  which  is  adjustably  secured  by  two  cap  screws.  After 
the  first  cut,  the  dies  work  progressively  and  a  blank  is  pierced  and  cut 
off  at  each  stroke  of  the  press,  and  falls  through  the  open  die  shoe  as  cut 
off.  The  cutting  off  punch  will  be  seen  to  be  longer  than  the  small  piercing 
punches  so  as  to  sever  the  piece  before  the  punches  come  into  contact  with 
the  stock.  As  pointed  out  at  another  place,  this  is  to  prolong  the  life  of 
the  punches. 

It  is  also  essential  to  make  the  stock  guide  slot  in  the  stripper  no  wider 
than  is  necessary  to  allow  the  stock  to  slide.  As  will  be  noticed,  the  cut- 
ting off  punch  G  is  cut  out  at  7  for  the  purpose  of  providing  room  for  the 
machine  steel  punch  plate  J  which,  with  the  cutting  off  punch,  is  secured 
to  the  punch  holder  B  by  fillister  head  screws  and  dowel  pins. 

The  second  operation  punch  and  die,  Fig.  333,  bend  the  blank  to  the 
form  at  B,  Fig.  331.  The  cast  iron  die  shoe  A  has  two  hardened  tool 
steel  blocks  B  mounted  upon  it  and  held  by  four  fillister  head  screws  through 
the  shoe.  The  forming  punch  C,  of  hardened  steel,  is  secured  by  four 
screws  to  the  cast  iron  punch  holder  D.  The  stops  E  locate  the  blank 
centrally  and  sidewise  over  the  die.  Spring  knockout  pins  are  provided 
for  both  the  punch  and  die.  The  right  tension  for  the  knockout  spring 
for  the  punch  can  be  secured  by  adjusting  the  screws  F,  while  the  knock 
out  spring  and  pins  in  the  die  have  means  of  adjustment  through  the 
screws  H  and  the  nuts  I  and  J. 

The  third  operation  punch  and  die  are  illustrated  by  Fig.  334.  The 
sectional  view  at  A  shows  the  simplicity  of  construction  of  these  tools. 
The  hardened  tool  steel  die  block  C  is  mounted  on  a  cast  iron  die  shoe  and 
held  with  screws  as  is  clearly  shown.  Gage  stops  D  locate  the  work  in 
relation  to  the  V  form  of  the  die.  The  forming  punch  F,  which  is  of  neces- 
sity very  slender  and  therefore  subject  to  breakage,  has  to  be  reinforced 
without  in  any  way  interfering  with  the  die  or  the  work.  The  way  in 
which  this  is  accomplished  is  shown  at  B,  Fig.  334.  The  forming  punch 


244 


PUNCHES  AND  DIES 


BENDING  AND  FORMING  TOOLS 


245 


rests  in  the  slot  H  and  is  secured  to  the  webs  J  of  the  punch  holder  by  six 
screws,  as  indicated  by  dotted  lines  G.  The  distance  I  is  ample  to  clear  the 
width  of  the  die  block  so  there  is  no  interference. 

By  using  this  method  of  mounting  very  thin  forming  punches  the  danger 
of  bending  or  breaking  is  eliminated,  and  the  replacing  of  old  punches  is 
simplified. 


Blank  and  Pierce 
1st  Op. 


£2nd  Op. 


C          3rd  Op.          D    4th  Op. 
FIG.  335.  —  Operations  in  a  formed  and  bent  spring  clip 


FIG.  336.  —  The  first  operation  forming  tools 
FLOATING  WORK  SUPPORTS 

The  principle  shown  in  Fig.  334  of  striking  a  blank  in  the  middle  for 
bending  up  the  ends  hair  pin  fashion  is  often  applied  with  first  bending 
operations  as  well  as  with  the  second  or  forming  operation  illustrated  in 
that  view.  And  where  a  blank  is  so  bent  to  a  U  form  with  arms  that 
require  closing  together,  as  with,  say,  some  form  of  spring  clip,  the  work 
may  at  times  be  supported  upon  a  type  of  floating  holder  that  allows  the 
piece  to  be  carried  down  into  the  die  and,  upon  its  release  from  the  upper 
die  or  punch,  to  be  lifted  clear  from  the  dies  for  removal  by  the  operator. 


246 


PUNCHES  AND  DIES 


FIG.  337.  —  The  bending  dies  for  the  spring  clip 


FIG.  338.  —  The  bending  die  construction 


BENDING  AND  FORMING  TOOLS 


247 


A  case  in  point  is  illustrated  by  the  bent  and  formed  spring  pin,  Fig. 
335,  which  is  manufactured  from  TV-m.  steel,  J  in.  wide.  This  steel  piece  is 
first  pierced  and  cut  off  to  length  in  dies  like  those  in  Fig.  156,  Chapter  V. 
It  is  then  placed  in  the  forming  dies,  Fig.  336,  where  the  central  loop  and 
the  various  other  bends  are  made  crosswise  of  the  stock.  These  dies  are 
simply  upper  and  lower  shoes  of  cast  iron  with  hardened  steel  forming 
blocks  inserted  in  their  faces  and  secured  by  fillister  head  screws  and  dowels. 
The  die  blocks  are  provided  with  end  shoulders  to  form  a  locating  device 
for  stopping  the  end  of  the  blank  from  passing  over  the  end  of  the  die. 
One  down  stroke  of  the  press  forms  the  blank  to  the  corrugated  slope  at 
B,  Fig.  335.  It  is  then  ready  for  the  bending  dies,  Figs.  337  and  338. 

The  latter  drawing  shows 
the  work  in  place  and  bent  up 
by  the  downward  pressure  of 
the  punch.  The  punch  is  a 
T-shaped  tool  with  a  narrow 
portion  crosswise  of  the  end  to 
produce  the  bending  action  at 
the  middle  of  the  work;  the 
back  of  the  punch  is  virtually 
reinforced  for  rigidity  and 
strength  by  the  portion  of  the 
body  which  has  not  been  cut 
away  in  forming  the  bending 
section.  This  leaves  the  cross 
section  of  the  punch  as  at  A, 
Fig.  338,  with  a  full  half  circle 
which  is  used  as  a  guide  in  the 


FIG.  339.  —  The  finish  forming  dies 


descent  of  the  punch  into  the  die,  the  letter  being  bored  at  the  center  to 
form  a  bearing  for  the  back  of  the  cylindrical  punch  surface. 

The  die  blocks  are  in  the  form  of  jaws  with  well  rounded  upper  corners 
and  with  stop  gages  at  each  end  for  centering  the  work.  As  the  punch 
descends  and  forces  the  work  between  these  jaws,  the  action  of  the  two 
elements,  punch  and  jaws,  is  to  bend  the  work  to  a  small  circle  in  the 
middle  corresponding  to  the  similar  form  on  the  end  of  the  punch.  This 
circular  curve  merges  into  the  concave  curve  directly  above  on  the  punch 
and  the  die  jaws  are  so  shaped  as  to  conform  to  this  and  give  a  cleanly 
bent  piece,  like  C,  Fig.  335.  The  ends  of  the  work  spring  apart  as  the 
piece  is  removed  from  the  punch  on  its  up  stroke  and  a  fourth  operation  is 
used  to  close  the  ends  as  at  D,  in  the  same  engraving. 

It  is  here  that  the  carrier  is-  provided  to  receive  the  work  from  the 
operator,  allow  it  to  be  forced  down  into  the  dies,  and  finally,  return  it  to 
clear  position  for  removal. 


248 


PUNCHES  AND  DIES 


The  dies  are  represented  by  Figs.  339  and  340.  Referring  to  the  latter 
view,  the  work  is  shown  at  D,  in  the  dies,  with  the  dies  closed  upon  it.  It 
is  held,  however,  upon  a  small  arbor  or  pin  E,  which  holds  the  size  of  the 
loop  at  the  end  of  the  work  against  any  tendency  for  it  to  close  flat  when 
the  dies  are  pressed  against  it.  This  pin  is  carried  in  a  holder  F  which  is 
mounted  upon  a  spring  plunger  G  placed  vertically  in  the  back  of  the  die 
shoe  so  that  it  can  move  freely  when  released  by  the  dies. 

The  operator  places  the  work  over  this  pin  and  the  upper  die,  in 
descending,  carries  the  work  and  the  support  F  down  until  the  bend  is 


FIG.  340.  —  The  finish  forming  dies 

completed  by  the  squeezing  of  the  piece  between  the  dies,  then  on  the  up 
stroke,  the  spring  actuated  device  lifts  the  work  clear  and  it  is  removed 
from  the  end  of  the  short  pin  E. 

While  the  dies  here,  as  in  previous  illustrations,  are  of  tool  steel,  hard- 
ened, there  are  various  examples  of  bending  and  forming  tools  where  all 
parts  are  of  machine  steel,  which  very  often  is  not  even,  case  hardened. 
This  is,  of  course,  with  dies  used  on  small  lots  of  work  or  where  the  general 
conditions  of  operation  are  such  as  to  impose  little  wear  upon  their  surfaces. 

A  FLAT  FORMING  OR  CURLING  JOB 

The  tools,  Figs.  341  to  345  inclusive,  are  for  making  the  piece  shown  in 
Fig.  342.  This  is  a  triangular  part,  blanked  and  formed  from  ^V  in.  stock. 
It  is  curled  or  formed  at  the  edges  and  one  end  of  each  curl  is  closed  by 
pinching  under  a  punch. 

The  blanking  is  done  in  the  tools  shown  in  Fig.  341.     These  are  of  the 


BENDING  AND  FORMING  TOOLS 


249 


progressive  order  and  before  the  piece  is  blanked  from  the  strip  it  is  stamped 
as  indicated,  on  the  face.  The  progressive  tools  need  little  in  the  way  of 
description  but  there  is  one  feature  to  which  attention  should  be  called: 
These  blanked  parts  are  to  be  curled  or  formed  up  at  the  ends  as 
pointed  out,  and  to  assure  this  operation  being  performed  satisfactorily, 
the  edges  where  the  curl  is  required  are  bent  very  slightly,  as  indicated  by 


FIG.  341.  —  Progressive  stamping  and  blanking  dies 


A 

FIG.  342.  —  The  work  before  and  after  curling  and  forming 

the  sketch  at  A,  Fig.  342.  Without  this  starting  edge  there  would  be  no 
assurance  that  the  curl  would  be  started  correctly  in  the  second  operation 
dies.  So  the  blanking  tools,  Fig.  341,  are  made  with  the  edge  slightly 
chamfered  off  from  the  blanking  punch,  as  will  be  plainly  seen  upon  in- 
spection of  that  engraving.  At  first  thought  it  might  be  expected  that  there 
would  be  difficulty  in  cutting  out  the  blank  with  a  punch  so  chamfered  on 
its  corners,  but  in  practice  no  such  trouble  has  arisen.  The  work  comes 
out  oH)he  dies  with  a  clean  edge  slightly  bent  up  as  desired.  Probably 


250 


'.PUNCHES  AND  DIES 


FIG.  343.  —  The  end  curling  die 


FIG.  344.  —  The  end  curling  die 


BENDING  AND  FORMING  TOOLS 


251 


because  the  metal  is  of  such  light  gage,  the  beveled  edge  of  the  punch  acts 
to  "pinch  off"  the  material  after  it  has  turned  the  edge  as  required. 

When  the  blank  is  placed  in  the  forming  or  curling  tools,  Figs.  343  to 
345,  it  lies  flat  in  the  die  as  seen  in  the  latter  view,  and  the  edges  are  up- 
turned so  that  when  the  forming  slides  or  jaws,  J  are  forced  forward,  the 
metal  blank  naturally  follows  up  and  around  the  inside  of  the  concaved 
jaw  ends  and  rolls  into  a  neat  curve. 


FIG.  345.  —  Dies  shown  in  Fig.  344 

The  jaws  J  are  actuated  by  the  plungers  K  carried  by  the  punch  holder. 
They  are  provided  with  wedge  shaped  surfaces  near  their  lower  ends,  and 
these  inclines,  after  the  plunger  ends  are  well  down  and  supported  in  their 
guides  in  the  die  base,  force  the  sliding  jaws  /  forward  to  do  their  work. 
The  punch  L  is  a  spring  plunger  with  a  large  head  which  serves  to  hold  the 
blank  in  position  in  the  die  during  the  forming  operation.  The  blank  rests 
between  the  two  angular  faces  of  the  jaw  housings  at  M  and  a  tool  steel 
block  fitted  in  at  N.  At  the  side  of  the  plunger  L  there  are  two  small 
punches  0  which  are  adapted  to  strike  the  top  of  the  curl  on  the  work  and 
pinch  one  end  down  to  the  form  shown  in  Fig.  342,  B.  The  spring  plunger 


252 


PUNCHES  AND  DIES 


L  has  sufficient  movement  in  its  holder  to  allow  the  latter  to  descend  for 
some  distance,  after  the  plunger  starts,  to  hold  the  blank,  and  during  this 
continued  travel  the  work  is  curled  up  and  the  ends  flattened. 

On  the  up  stroke  of  the  punch  holder,  the  sliding  jaws  J  are  withdrawn 
from  the  work  by  the  action  of  the  springs  P  and  the  spring  plunger  L  re- 
leases the  finished  piece. 

The  jaws  /  which  do  the  forming  are  of  tool  steel,  hardened.  They 
slide  in  obliquely  planed  seats  in  the  die  shoe  and  are  held  in  position  by 
machine  steel  cover  plates.  The  beveled  plungers  K  which  operate  the 
jaws  are  also  of  tool  steel,  hardened. 

SPRING  FORMING  WITH  SLIDING  JAW  DIES 

These  dies  with  sliding  jaws  and  similar  devices  for  bending  up  a  blank 
or  for  forming  the  ends  into  the  desired  form  are  often  known  as  compound 
bending  or  forming  tools  to  distinguish  them  from  the  more  commonly 


FIG.  346.  —  Spring  forming  die 

used  plain  die  with  simple  bending  punch  and  fixed  die  jaws.  The  com- 
pound type  is  frequently  employed  for  such  operations  as  spring  bending 
or  forming  and  an  example  of  this  class  of  work  is  presented  in  Fig.  346 
herewith. 

This  illustration  represents  the  cross  section  of  a  die  for  performing  the 
last  operation  on  the  flat  spring  shown  at  X,  while  Y  shows  the  spring  as  it 
comes  to  the  die.  The  operation  of  the  die  is  as  follows:  The  work  is 
placed  on  the  lower  part  of  the  die  between  small  gage  pins,  which  are  not 
shown.  The  press  is  tripped;  and  as  the  upper  part  of  the  die  or  the  punch 


BENDING  AND  FORMING  TOOLS  253 

descends,  the  ends  of  the  spring  are  turned  up  into  vertical  position  by  the 
L-shaped  piece  A  forcing  the  steel  down  into  the  groove  cut  through  the 
square  head  plunger  B.  As  the  upper  half  of  the  die  continues  to  descend, 
the  plunger  B  is  carried  down  against  the  action  of  a  coil  spring  within  the 
barrel  C.  The  square  steel  plate  D  is  threaded  to  fit  the  thread  on  C  and 
is  fastened  to  the  cast  iron  base  of  the  die.  The  plunger  B  is  forced  nearly 
down  to  the  top  of  the  barrel  C  when  the  wedge  engages  the  slide  G,  which 
is  forced  toward  the  center  of  the  die  and  thus  starts  to  form  that  end  of 
the  work  around  A.  As  the  downward  motion  continues,  the  other 
wedge  engages  the  slide  K  and  thus  folds  over  the  other  end  of  the  work. 
While  this  part  of  the  operation  is  being  done,  B  is  stationary  and  A 
is  being  forced  upward  against  two  heavy  coil  springs,  only  one  of  which  is 
shown  at  P.  These  springs  are  located  in  diagonally  opposite  corners  of 
the  rectangular  upper  end  of  the  steel  part  A.  In  the  other  two  corners 
are  hold-up  bolts  that  also  act  as  guide  pins.  One]of  these  is  shown  at  Q. 
As  the  head  of  the  press  ascends,  the  slides  G  and  K  are  pulled  back  against 
stops  by  the  coil  springs  R  as  shown.  There  are  two  of  these  springs  on 
each  slide,  arranged  in  the  form  of  a  V,  to  pull  on  each  slide.  Bolts  pass 
through  the  holes  M  and  N  to  fasten  the  upper  half  of  the  die  to  the  ram  of 
the  press. 

PROGRESSIVE  TYPE  OF  DIES  FOR  BENDING 

As  already  noted,  in  connection  with  the  dies  in  Fig.  341,  bending  and 
forming  dies  are  arranged  on  the  progressive  order  to  allow  a  series  of 
operations  to  be  accomplished  simultaneously  in  a  set  of  tools.  Such 
operations  may  include  piercing,  bending,  and  blanking;  or  piercing, 
cutting  off,  and  curling;  etc.  Some  illustrations  follow,  these  being  shown 
in  connection  with  some  simple  bending  work  on  parts  used  in  conjunction 
with  the  pieces  made  by  the  progressive  type  of  dies. 

The  handle  A}  Fig.  347,  consists  of  three  parts,  the  wire  grip,  the  wire 
loop,  and  the  strap  for  attaching  the  handle  to  a  box.  Beginning  with  the 
wire  grip  there  are  three  essential  operations;  cutting  the  blank  from  the 
rod,  bending  the  blank  to  shape  for  the  hand  hole,  and  curling  the  ends  for 
the  attachment  of  the  link. 

The  sketch,  Fig.  348,  is  a  diagram  of  the  press  attachment  used  for  the 
first  two  operations.  The  machine  used  was  not  a  satisfactory  one  for 
the  purpose  but  no  long  stroke  press  was  available  so  this  attachment  was 
devised.  The  device  fastens  to  the  front  of  the  press  and  is  operated  by 
the  balance  arm ;  since  but  little  power  is  required  it  works  satisfactorily. 
The  fixture  requires  little  explanation.  As  part  A  descends  it  comes  in 
contact  with  the  parts  BB,  causing  them  to  swing  about  their  pivots  (7(7, 
forcing  the  blank  to  take  the  shape  of  the  form  E,  also  shown  at  F.  The 
return  stroke  of  the  press  withdraws  BB  allowing  the  removal  of  the  finished 


254 


PUNCHES  AND  DIES 


piece  and  the  insertion  of  a  blank  ready  for  the  operation  to  be  repeated. 
Following  the  bending  operation,  the  ends  are  curled  to  receive  the  link 
G,  and  lastly  closed  over  the  link  as  shown  at  H. 

The  method  of  curling  the  ends,  which  are  completed  in  two  operations, 
is  illustrated  by  Figs.  349  and  350.  As  can  be  seen  in  Fig.  349,  the  handle 
is  placed  flat  in  the  die,  the  ends  against  a  stop  while  a  spring  clamp  holds 
it  in  place.  As  the  punch  descends  it  forces  the  handle  into  the  grooves  in 
the  die  thus  giving  it  the  required  shape,  the  bend  being  made,  of  course, 
far  enough  from  the  ends  to  leave  sufficient  material  to  complete  the  loop. 
Following  this  operation,  the  link  is  placed  in  position  and  the  loop  closed 
with  the  tools  in  Fig.  350. 

The  making  of  the  link  or  wire  loop  consists  of  essentially  three  oper- 
ations :  cutting  off  the  blank,  bending  the  ends,  and  curling  to  complete  the 


FIG.  348  FIG.  351  FIG.  353 

FIGS.  347-353.  —  Ammunition  box  and  hardware  and  the  tools  used 

loop.  These  operations  are  shown  in  Fig.  351.  The  rod  is  sheared  to  the 
proper  length  by  a  simple  operation  that  requires  no  explanation.  Fol- 
lowing shearing,  the  blank  passes  to  a  double  punch  and  die,  Fig.  352, 
where  the  ends  are  bent  to  the  form  shown  at  B,  Fig.  351,  thence  to  the 
second  part  of  the  machine  where  it  is  again  bent  or  curled  at  C,  thus 
joining  the  ends  and  completing  the  loop. 

The  first  bending  operation  leaves  the  link  clinging  to  the  punch  or 
die,  and  to  make  certain  of  its  removal  and  transfer  to  the  next  operation, 
with  safety  to  the  operator,  the  knockout  and  transfer  devices  shown  at  A 
and  B}  Fig.  352  are  utilized.  The  knockout  is  very  simple  and  can  be 


BENDING  AND  FORMING  TOOLS 


255 


readily  understood  from  the  sketch;  the  transfer  device,  however,  requires 
a  brief  explanation : 

During  the  forming  of  the  blank  the  two  wedge-shaped  pieces  D  act  on 
the  tapered  portion  G  of  the  transfer  device  B,  moving  it  toward  the  punch 
until  the  notches  E,  Fig.  353,  grip  the  link.  The  return  stroke  of  the 
press  causes  the  device  to  move  in  the  opposite  direction  sufficiently  to 
bring  the  link  into  position  for  the  final  operation  which  is  performed  by 
the  punch  F,  Fig.  352.  The  action  of  the  punch  F  is  similar  to  that  of 
punch  C  and  simply  bends  the  link  in  the  center,  joining  the  two  ends  and 
completing  the  loop. 

MAKING  THE  STRAP 

The  strap  which  fastens  the  handle  to  the  box  is  next  in  order  and  its 
manufacture  consists  of  five  operations;  punching  the  screw  holes,  blank- 
ing, preliminary  curling  to  receive  the  link,  final  curling,  and  bending  the 
angle  at  the  end.  The  stock  from  which  these  straps  are  made,  is  2  by  TV 


J2-/T- 

E_:n: 


FIG.  355  FIG.  357  FIG.  358 

FIGS.  354-358.  —  Ammunition  box  and  hardware  and  the  tools  used 

in.  steel.  The  first  press  performs  three  operations  in  the  order  named. 
At  commencement  of  this  series  of  operations,  the  strip  of  steel  is  pushed 
under  the  stripper  in  Fig.  354,  to  a  point  where  the  end  will  just  be  sheared, 
and  punching  and  shearing  then  take  place.  The  end  of  the  strip  is  then 
brought  up  against  the  stop  just  beyond  the  curling  die  and  the  operations 
take  place  in  the  order  already  indicated.  After  the  curling  operation, 
the  strap  is  left  in  the  shape  at  A,  ready  for  the  closing  of  the  loop.  The 
shape  and  position  of  the  curling  dies  are  shown  at  B.  Immediately  fol- 
lowing this  operation,  the  curling  is  completed,  joining  the  loop  and  strap, 
and  the  end  of  the  strap  is  then  bent  at  a  right  angle  for  fastening  to  the 
bottom  of  the  box. 

Fig.  355  shows  the  fixture  for  the  final  bending  operation  which  connects 


256  PUNCHES  AND  DIES 

the  strap,  loop,  and  handle.  Fig.  356  shows  the  tools  for  bending  the  angle 
on  the  end  of  the  strap,  these  being  placed  in  the  same  press  with  those  for 
forming  the  strap.  The  fixture  in  Fig.  355  is  used  as  follows:  The  long 
end  of  the  strap  is  placed  upright  in  the  slot  L  and  when  the  punch  M 
descends  it  causes  the  curved  end  to  bend  until  it  lies  close  to  the  body  of 
the  strap,  thus  forming  the  loop  for  enclosing  the  link.  During  this  op- 
eration, the  loop  is  held  in  place  by  the  handle  which  is  laid  back  over  N. 
Bending  for  the  angle  requires  no  explanation,  this  being  performed  at  the 
same  time  as  the  final  curling. 

The  small  angle  D,  Fig.  347,  serves  to  fasten  the  side  of  the  box  securely 
to  the  bottom  and  is  made  in  four  operations.     These  are:  punching  for 


0 

0                                                                          0                             A                                            0 

0 

5>- 

0 

o 

10^8 
;  i           Steel  l/zz   Thick 

*•      o                   \ 

Slot    5/io"  Wide 


FIG.  359.  —  Sequence  of  operation  in  blanking,  slitting  and  slotting 

screw  holes,  shearing,  countersinking,  and  bending.  The  punching,  shear- 
ing and  bending  operations  are  similar  to  those  already  shown  for  the 
handle  strap  and  the  countersinking  is  performed  in  an  ordinary  drill  press. 
Fig.  357  illustrates  the  arrangement  of  the  tools  in  the  press  for  these 
operations.  They  are  simple  and  self-explanatory. 

The  latching  device  for  the  cover  consists  of  the  latch  on  the  cover  B, 
Fig.  347,  and  a  formed  hook  attached  to  the  bottom  of  the  box.  The 
construction  of  the  latch  requires  only  very  simple  operations  of  punching 
and  shearing  for  the  spring  plate,  while  the  portion  which  engages  the 


BENDING  AND  FORMING  TOOLS  257 

hook  is  forged.     The  making  of  the  spring  plate  and  latch  requires  no 
tools  of  special  interest  and  heed  not  be  described. 

The  hook  used  in  connection  with  the  latching  device  is  the  heaviest 
work  on  any  of  these  parts  and  there  are  four  operations:  Punching, 
blanking,  countersinking,  and  bending  to  form  the  angle.  The  finished 
hook  is  shown  at  (7,  Fig.  347.  The  punching,  blanking,  and  bending  oper- 
ations are,  of  course,  all  performed  in  one  operation  in  a  press  and  the 
countersinking  in  a  drilling  machine.  Fig.  358  shows  the  arrangement  of 
the  tools,  including  the  die  for  the  angle,  which  is  formed  at  the  same  time. 

APPLICATION  OF  THE  SLITTING  PRINCIPLE 

In  connection  with  the  use  of  bending  and  forming  dies  there  is  now 
and  then  a  piece  of  work  where  an  unusual  operation  is  required  before 
the  real  work  of  forming  can  be  accomplished.  This  preparatory  opera- 
tion, as  it  might  be  called,  consists  in  cutting  a  slit  with  a  pair  of  dies  to 


r~ 


FIG.  360.  —  A  slitting  die 

provide  two  edges  for  folding  or  bending  back  as  in  forming  a  channel  or 
similar  opening  in  a  sheet 'metal  member.  A  case  in  point  is  herewith 
illustrated  by  the  sketches  in  Fig.  359  where  C  is  a  machine  part  formed 
up  to  a  shallow  channel-shaped  piece  with  a  slot  -fa  in.  wide  nearly  the  full 
length. 

The  blank  for  this  part  is  shown  at  A  with  a  series  of  holes  pierced 
around  the  edge.  At  B  is  shown  the  piece  with  the  slit  cut  along  the 
center  line  and  two  small  triangular  tips  formed  up  at  the  end  of  the  slit. 

The  slitting  tools  are  shown  by  Figs.  360  and  361,  and  referring  to  the 
latter  view,  the  slitting  punch  proper  will  be  seen  at  D  and  the  piercing  and 
forming  punches  for  the  triangular  points  E  are  located  at  G.  These 
latter  punches  are  made  with  half-inch  round  shanks  fitted  into  holes 
bored  in  the  punch  holder.  Their  sharp  V  edges  are  abutted  against  the 
ends  of  the  slitting  punch  D  and  their  ends  project  J  in.  below  the  edge  of 
that  punch  to  perform  their  work  before  the  slit  is  cut. 

Referring  to  the  sectional  view  to  the  left,  the  slitting  die  will  be  seen 


258 


PUNCHES  AND  DIES 


Slitting  Punch 
D 

Piercing  and  Forming 
Punches 


FIG.  361.  — Slitting  dies 


FIG.  362.  —  Forming  tools  that  follow  the  slitting  die 


BENDING  AND  FORMING  TOOLS 


259 


at  H.  It  is  made  in  two  sections,  divided  along  the  longitudinal  center 
line,  and  one  side  is  relieved  for  a  depth  of  TV  in.  as  indicated  to  allow  the 
slitting  punch  to  shear  the  material  past  the  die  edge  formed  at  the  shoulder 
/.  The  slitting  punch  itself  is  fV  in.  thick  back  of  the  cutting  edge  and 
has  a  body  thickness  of  1  j  in.  for  attachment  to  the  punch  holder  where  it 
is  secured  by  fillister  head  screws  and  dowel  pins.  The  punches  and  die 
sections  are  of  tool  steel,  hardened. 

The  forming  tools  are  seen  in  Figs.  362  and  363  and  in  the  former  en- 
graving the  finished  work  is  also  shown.  The  construction  of  the  tools 
will  be  understood  upon  referring  to 
the  section  in  Fig.  363.  The  lower 
die  /  is  of  tool  steel  secured  by  fillis- 
ter head  screws  and  dowel  pins  in  a 
seat  in  the  shoe  or  base.  The  upper 
die  J  is  similarly  fixed  in  the  punch 
holder.  The  lower  die  is  fitted  with 
a  tongue-shaped  member  K  which 
serves  as  a  punch  to  bend  up  the  ma- 
terial along  the  edges  of  the  slit,  and 
similarly  the  punch  I  is  grooved  at  L 
to  form  a  die  for  this  forming  oper- 
ation. Thus,  as  the  blank  is  forced 
down  into  the  main  forming  die  I  its 
sides  are  folded  up  into  the  channel 
form  and  as  it  nears  the  bottom  of  the 
die  the  slitted  portion  is  bent  up  and 
formed  by  the  punch  section  K  and 
die  slot  L  ^IG-  ^63.  —  End  view  of  forming  die  ' 

The  blank  is  located  on  the  die  by  the  gage  pins  shown  in  the  photo- 
graph, Fig.  362. 

A  SECTIONAL  CONSTRUCTION 

The  coin  register  part  shown  in  Fig.  364  is  produced  from  0.035-in. 
stock  by  the  tools  in  Figs.  365  and  366.  These  are  of  interest  because  of 
the  unusual  form  of  the  piece  and  because  of  the  sectional  construction  of 
the  dies.  The  blanking  tools  are  represented  by  Fig.  365. 

They  consist  of  the  built-up  die  and  punch  seen  side  by  side,  where  the 
sections  of  the  punch  are  particularly  clear.  The  die  is  similarly  con- 
structed but  the  individual  parts  are  obscured  by  the  stripper.  The  special 
features  of  the  work  are  the  right-angle  bends  at  each  end  of  the  base  and 
the  curved  deflectors  in  front  which  are  formed  up  to  a  flaring  curve  di- 
verging from  the  center  outwardly.  The  flat  base  is  also  curved  along  its 
edge  as  indicated  in  the  drawing  and  the  sections  there  reproduced  give  the 
slope  of  the  curves  at  various  points. 


260 


PUNCHES  AND  DIES 


FIG.  364.  —  An  unusual  shape  to  be  formed 


FIG.  365. •• —  Sectional  blanking  tools 


FIG.  366.  —  The  bending  and  forming  dies 


BENDING  AND  FORMING  TOOLS 


261 


The  blank  is  placed  for  forming,  on  the  pressure  pad  and  knock  out  A, 
Fig.  366,  which  has  a  locating  ledge  at  the  front  with  a  curved  face  leading 
up  to  it  to  produce  the  curve  along  the  edge  of  the  work  at  B  (Fig.  364). 
The  end  forming  die  blocks  are  at  CC  for  bending  up  the  wings  of  the  blank 
at  DD  (Fig.  364).  At  the  back  of  the  die  are  secured  two  blocks  EE  for 
forming  up  the  curved  deflectors  FF  (Fig.  364).  The  back  of  the  blank 
rests  against  stops  GG  when  the  work  is  placed  in  the  dies.  As  the  upper 
die  descends  the  punch  block  A  forces  the  blank  down  into  the  face  of  the 
pressure  pad  A  and  continuing  downward,  the  ends  of  block  A  cause  the 
ends  of  the  work  to  be  bent  up  at  right  angles  against  the  die  blocks  CC. 
At  the  same  time  the  curved  end  punch  blocks  E'E',  form  the  ears  F  against 
the  die  blocks  E  at  the  back,  and 
the  bent  up  lip  along  the  front  edge 
of  the  blank  at  B  is  formed  be- 
tween the  bottom  of  punch  block 
A'  and  the  corresponding  curved 
surface  at  A. 

When  the  upper  die  or  punch 
head  ascends,  the  pressure  pad  and 
ejector  A  follow  the  punch  upward 
and  lift  the  formed  work  out  of  the 
dies. 

All  parts  in  the  way  of  punch 
and  die  members  are  of  tool  steel, 
hardened,  and  the  punch  holder 
and  die  shoe  are  of  machine  steel. 
The  bolster  for  the  blanking  die 
sections  is  a  large  casting  planed 


END  OF  BLANKING  PUNCH 


,z> 


c 

FIG.  367.  —  Curling  operation 


out  lengthwise  to  form  a  seat  for  the  various  blocks  which  made  up  the 
die  as  a  whole.  The  stock  stop  for  the  material  for  the  blank  is  of  the 
trigger  type  and  is  shown  at  S,  Fig.  365.  There  are  two  guide  pins  in 
this  die  base  for  alining  the  punch  holder,  and  similarly  two  pins  are 
used  in  the  forming  dies,  Fig.  366. 


A  WORD  ABOUT  CURLING 

In  several  places  certain  operations  in  the  line  of  curling  have  been 
shown  and  a  final  word  may  be  added  at  the  close  of  this  chapter  in  refer- 
ence to  this  process.  It  has  been  pointed  out  in  connection  with  the  oper- 
ations shown  in  Fig.  342  that  the  end  of  the  blank  should  be  made  with  a 
slight  initial  curl  to  assure  its  finishing  properly  when  passed  through  the 
curling  dies.  The  punch  for  blanking  should  therefore  be  made  with  the 
Corners  taken  off  to  leave  a  round  bend  on  the  blank  as  at  A,  Fig.  367,  so 


262  PUNCHES  AND  DIES 

that  in  the  curling  dies  B  the  ends  of  the  work  will  follow  the  concave  die 
form  and  complete  the  circle  as  at  C. 

If  the  end  of  the  blank  is  cut  off  square  as  at  D  the  subsequent  curl  will 
be  in  the  form  shown  at  C  with  the  end  brought  down  to  the  body  of  the 
blank  at  D  but  not  curled  in  as  it  should  be.  This  is  overcome  by  making 
the  blanking  punch  as  stated,  with  the  corners  rounded  as  at  A. 


CHAPTER  XI 

BENDING,  FORMING,   AND    OTHER   DIES   APPLIED   TO   SPE- 
CIFIC  LINES   OF  WORK 

The  bending  and  forming  tools  illustrated  in  this  chapter  are  presented 
to  show  particular  applications  of  such  equipment  in  conjunction  with 
other  classes  of  dies,  such  as  blanking,  piercing,  and  other  tools,  for  per- 
forming in  sequence  the  operations  necessary  in  manufacturing  certain 
parts  for  typewriters,  calculating  machines,  coin  registers,  etc.  It  is 
believed  that  this  method  of  presentation  cannot  fail  to  be  of  service  as 
something  of  a  guide  to  those  laying  out  and  constructing  sets  of  dies  for 
work  of  somewhat  similar  character.  0 

The  arrangement  of  this  chapter  also  gives  a  further  opportunity  for 
illustrating  a  variety  of  press  tools  which,  while  falling  within  some  one 
or  more  of  the  general  classes^  already  described  under  preceding  chapter 
heads,  have,  nevertheless,  certain  features  that  are  peculiar  to  themselves 
and  justify  a  description  in  the  present  section  of  this  book. 

BLANKING,  PIERCING,  AND  FORMING  TOOLS  FOR  TYPEWRITER  WORK 

The  tools  that  follow  are  used  in  the  manufacture  of  a  sheet  metal 
member,  known  as  a  universal  bar,  for  the  Noiseless  typewriter. 

This  part  is  9f  in.  long  and  is  bent  up  to  a  quarter  circle  of  5  f-in.  radius, 
as  shown  in  Fig.  368.  It  has  three  lugs  or  arms  projecting  from  the  lower 
edge,  which  are  offset  in  the  blanks  and  then  bent  around  at  right  angles 
to  the  body  of  the  bar  itself.  It  is  made  from  sheet-steel  stock  0.040  in. 
thick,  and  one  piece  is  required  for  each  typewriter. 

Figs.  369  and  370  illustrate  the  blanking  tools  used  in  the  production 
of  these  sheet-metal  parts.  The  die  is  of  simple  construction,  and  the 
punch  is  of  a  form  requiring  little  explanation  in  detail.  However,  the 
length  in  proportion  to  the  width  of  the  projecting  portions  that  form  the 
lugs  on  the  blanks  is  such  that  a  considerable  degree  of  care  and  judgment 
was  necessary  in  machining  and  hardening  these  tools  in  order  to  prevent 
a  degree  of  deformation  which  would  make  the  punch  work  improperly  in 
the  die.  Both  punch  and  die  are  mounted  upon  heavy  blocks,  the  bolster 
for  the  die  being  of  the  standard  form  used  in  the  factory  for  a  large  share 
of  the  press  tools. 

The  proportions  of  the  die  proper  will  be  seen  from  Fig.  369,  which 

263 


264 


PUNCHES  AND  DIES 


shows  the  layout  as  indicated  by  the  opening  in  the  stripper  and  also  the 
width  of  the  stock  guide  slot  in  the  underside  of  the  stripper.  The  dotted 
lines  in  the  top  of  the  plate  show  that  the  width  of  the  guide  is  sufficient 
to  admit  stock  wide  enough  for  two  rows  of  blanks,  so  that  the  material  is 
reversed  for  the  second  passage  through  the  press  and  there  is  very  little 
waste  along  the  edges  of  the  strip  of  stock  or  between  the  projecting  lugs. 


3.77— 


>j<--  /56ff-J 
k  ...........  3.77-  ........  -H 


FIG.  368.  —  Details  of  universal  bar  for  typewriter 


''"*t      ,...-|*/S5cm?sx 


r 4 

FIG.  369.  —  The  blanking  die 


0040*12% 

Stock 


The  second  die,  Fig.  371,  is  used  for  punching  out  the  seven  openings. 
In  this  process  a  greater  portion  of  the  material  is  cut  away.  The  work  is 
shown  at  the  front  of  the  die.  It  will  be  noticed  that  there  are  also  six 
round  pierced  holes  in  the  lugs.  As  a  matter  of  fact,  this  piercing  operation 
is  performed  in  a  subsequent  process,  the  blank  being  shown  here  in  this 
condition  to  indicate  its  appearance  before  twisting  of  the  lugs  occurs. 

These  dies,  like  the  blanking  tools  shown,  are  simple  in  construction, 


BENDING  AND  FORMING  DIES 


265 


although  they  have  been  laid  out  and  finished  with  great  care  to  assure 
satisfactory  operation  under  the  punch  press.  In  working  material  of  this 
thickness,  where  such  narrow  portions  of  the  stock  are  left  as  are  indicated 
in  the  illustration,  it  is  important  that  the  material  shall  have  no  opportu- 
nity for  creeping  under  the  punching  action  t)f  the  tools.  Otherwise,  the 
edges  become  deformed,  the  inner  openings  formed  by  punching  out  the 
stock  become  twisted,  and  the  job  is  generally  unsatisfactory. 


FIG.  370.  —  The  blanking  tools 


FIG.  371.  —  Dies  for  second  operation 


PIERCING  Six  HOLES  AT  ONCE 

Referring  to  Fig.  372,  the  press  tools  at  the  left  perform  the  operation  of 
piercing  the  six  holes  in  the  blank.  Here,  a  sectional  construction  is  used, 
as  indicated.  The  work  is  nested  under  the  stripper  plate,  against  suitable 
end  stops  and  back  stops,  and  is  thus  retained  against  movement  during 
the  downstroke  of  the  punch.  The  latter  has  a  block  that  is  provided  with 
corner  posts,  thus  making  a  pillar-die  construction.  As  will  be  seen,  the 
small  piercing  punches  are  all  carried  in  sockets  sufficiently  large  to  assure 
stability  of  the  punches  and  prevent  their  deflection  under  the  action  of 
piercing  this  0.040-in.  piece  of  stock. 

Each  of  the  punch  members  as  shown  is  fastened  securely  to  the  block 
by  fillister  head  screws  and  an  adequate  number  of  dowels,  while  the  holders 
for  the  piercing  punches  are  located  outside  of  the  punches  proper  in  holes 
laid  out,  and  accurately  indicated  and  bored  in  correct  positions  on  the 
face  plate  of  a  lathe. 

The  tools  at  the  center  in  Fig.  372  are  for  forming  up  the  blank  to  the 
arc  of  a  circle  and  bending  down  the  middle  lug  or  arm  nearly  halfway  to 


266  PUNCHES  AND  DIES 

its  right  angle  position  to  the  body  proper.  For  this  operation  the  work 
is  nested  against  a  stop  at  one  end.  The  punch  in  descending  with  its 
curved  lower  contact  face  forms  the  blank  down  into  the  curved  seat  on  the 
top  of  the  die,  the  projecting  hub  or  pilot  at  the  middle  of  the  punch  en- 
gaging with  the  square  opening  at  the  middle  of  the  length  of  the  work, 
thus  preventing  the  work  from  traveling  either  to  the  right  or  the  left. 


FIG.  372.  —  Dies  for  forming  the  universal  bar 

Looking  closely  at  Fig.  372,  it  will  be  seen  that  there  are  stop  lugs  at  both 
the  back  and  the  front  of  the  die  to  make  of  the  latter  a  suitable  nest  in 
which  the  straight  blank  will  rest  securely  during  the  downstroke  of  the 
press,  under  which  it  is  transformed  into  the  curved  article. 

At  this  same  setting  the  two  grooves,  or  beads,  running  longitudinally 
the  full  length  of  the  work  are  formed  up  to  stiffen  the  job  so  that,  when 
bent  to  the  arc  of  the  circle,  there  will  be  little  likelihood  of  its  being  twisted 
or  deflected  in  action.  The  stiffening  ribs,  although  shallow,  are  sufficiently 
deep  to  add  materially  to  the  strength  of  the  parts  and  greatly  increase  its 
resistance  to  any  forces  tending  to  open  the  arc  out  toward  a  straight  line 
or  to  twist  the  curved  portion  about  its  major  axis.  The  use  of  ribs  in  this 
way  forms  a  convenient  method  of  strengthening  sheet-metal  work  with- 
out increasing  the  weight  and  adds  practically  nothing  to  the  cost  of  manu- 
facture, as  the  forming  of  the  grooves,  which  also  form  the  beads,  or  ribs, 
on  the  opposite  side,  is  done  at  the  same  stroke  of  the  press  as  the  body  of 
the  piece  is  bent  to  the  arc  of  the  circle  and  the  central  lug  bent  halfway 
down. 

The  tools  at  the  right,  Fig.  372,  are  the  most  interesting  of  the  group 
in  this  view,  and  details  will  be  seen  in  Fig.  373.  It  will  be  noticed  that 
here  the  work  is  nested  upon  the  convex  face  of  the  lower  die,  and  on 
this  die  block  it  rests  between  a  pair  of  pins  at  the  back  and  two  adjustable 
stop  screws  at  the  front.  Midway  of  the  width  of  the  die  will  be  seen  a 


BENDING  AND  FORMING  DIES 


267 


vertical  offset  portion  F  that  forms  the  bending  corner  over  which  the 
middle  lug  A,  Fig.  368,  is  bent  around  to  a  true  right  angle  to  the  tangent 
line  to  the  universal  bar.  The  lugs  at  either  end,  B  and  C,  Fig.  368,  are  bent 
down  to  a  position  parallel  to  the  central  lug  A  by  the  two  punch  members 
attached  at  the  right-  and  left-hand  sides  of  the  punch  block. 


FIG.  373.  —  Forming  die  for  universal  bar 

Referring  again  to  Fig.  372,  it  will  be  seen  that  the  concave  block  F 
is  arranged  to  act  as  a  pressure  pad  to  hold  the  blank  temporarily  during 
the  descent  of  the  press  ram,  while  the  punch  members  D,  E,  and  G  fold 
down  the  three  ears  or  lugs  to  the  right-angle  position.  The  movement 
necessary  after  the  pressure  block  seizes  the  work  is  about  f  in.,  and  this  is 
allowed  for  by  the  compression  springs  seated  between  the  block  H  and 
the  main  punch  block,  as  shown  in  Fig.  373. 

It  should  be  noticed  that  on  the  downstroke  of  the  press  the  first  thing 
that  happens  is  for  this  pressure  pad  H  to  drop  over  the  pilot  pins  KL,  so 
that  here  again  a  subpress  form  of  action  is  obtained  in  that  at  the  moment 
of  operating  upon  the  blank  the  punch  and  die  are  piloted  and  guided  to- 
gether by  the  pillars,  or  pins,  at  either  end. 

The  two  punch  members  D  and  E,  only  one  of  which  is  shown  in  Fig. 
373,  but  both  of  which  are  clearly  visible  in  Fig.  372,  are  in  the  form  of 
angles  with  stiff  uprights  and  bases,  the  latter  having  two  substantial 
screws  and  a  pair  of  dowels,  by  which  each  part  is  secured  to  the  punch  block. 

Similarly,  the  central  bending  punch  G,  Fig.  373,  is  made  with  a  right- 
angle  base  and  secured  by  a  pair  of  screws  and  dowels.  This  construction 
enables  the  part  to  be  fitted  up  to  the  work  conveniently  and  to  be  replaced 
in  case  any  part  should  wear  out  or  give  way. 


268 


PUNCHES  AND  DIES 


The  position  of  the  work  endwise  upon  the  lower  blank  when  nested 
for  the  downward  stroke  of  the  press  is  positively  secured  against  possible 
end  thrust  in  either  direction,  due  to  the  lateral  pressure  of  the  bending 
punches  D  and  E  by  the  pilot  M.  Upon  the  upstroke  of  the  press  the  work 
is  prevented  from  lifting  with  the  die,  due  to  the  binding  pressure  between 
the  inner  faces  of  the  bending  punches  D  and  E  by  a  shedder  operating 
between  these  punches  and  acting  downward  upon  the  work  and  holding 
it  upon  the  convex  upper  base  of  the  lower  die. 

OPERATIONS  ON  THE  MARGIN  STOP 

The  margin  stop  on  the  same  typewriter  is  made  in  the  form  illus- 
trated in  Figs.  374  and  375,  which  show  both  the  right-  and  left-hand  stops. 
It  will  be  seen  from  the  drawing  that  this  piece  is  of  sheet  stock  formed  up 
to  box  shape  with  a  clip  at  the  top,  by  which  it  may  be  lifted  and  moved 


TT- 


tV^'1 


?«  rn  1  >  n 

i     |  w>*  Mi 

i_o^— *  <VJ 


FIGS,  374-375.  —  The  two  margin  stops 

along  from  one  notch  to  another  on  the  stop  bar.  These  pieces  have  an 
opposite  working  side  for  the  right-  and  the  left-hand  stop  respectively,  and 
for  the  projecting  lugs  at  A,  which  constitute  the  stop  proper  and  which 
engage  the  corresponding  member  on  the  carriage,  thus  determining  the 
length  of  the  travel  of  the  carriage  in  either  direction.  The  material  for 
these  stops  is  sheet  steel,  0.040  in.  thick,  and  the  size  of  the  blank  punched 
out  prior  to  bending  is  approximately  2  in.  wide  by  2J  in.  long. 

The  first  operation  in  the  punch  press  is  performed  with  the  tools 
shown  in  Fig.  376,  illustrating  the  proportions  of  the  punch  and  die  with 
which  the  notches  at  the  top  and  the  bottom  of  the  stops  are  cut  out,  and 
a  rectangular  hole  is  pierced  near  one  edge.  These  openings  are  plainly 
seen  in  the  blanks  at  the  front  of  the  strip  of  stock  lying  near  the  die. 

BLANKING  DIE  ARRANGED  TO  SAVE  STOCK 

It  will  be  noticed  upon  examination  of  this  scrap  metal  that  the  stock 
is  passed  through  the  die  twice,  it  being  reversed  for  the  second  run,  so 
that  the  blank  which  is  considerably  narrower  at  the  top  than  at  the  bottom, 


BENDING  AND  FORMING  DIES 


269 


is  shown  reversed  on  the  second  run  of  the  material  through  the  dies  and 
points  the  other  way  from  its  position  in  the  first  run.  This  means  that 
very  little  material  is  wasted  between  adjacent  blanks,  as  compared  with 
the  waste  that  would  occur  if  the  material  was  run  through  only  once. 


FIG.  376.  —  Piercing  and  blanking  die 

With  the  broad  faces  of  the  blank  brought  closely  together  instead  of 
leaving  them  far  enough  apart  to  allow  the  narrow  top  to  fit  in  between 
on  the  second  run,  much  stock  would  be  wasted. 

Fig.  376  in  conjunction  with  Fig.  377  shows  the  construction  of  the 
tools  clearly.  The  strip  of  metal  feeding  first  under  the  punches,  Fig. 
377,  is  notched  by  the  irregular-outline  punch  D  and  pierced  by  the  square 
punch  E.  It  then  advances  under  the  blanking  "punch^F  where  the  end 
of  the  stock  is  stopped  by  the  spring  stop  pin  distinctly  shown  in  the  draw- 
ing. At  the  next  stroke  of  the  press  the  blanking  punch  cuts  out  the  blank, 
the  pins  in  the  punch  locating  the  stock  accurately  so  that  "the  blanking  is 
done  in  correct  position  relatively  to  the  openings  cut  by  the  piercing  punch. 
Following  this,  each  down  stroke  of  the  press  slide  finishes  a  blank. 


270 


PUNCHES  AND   DIES 


After  the  strip  has  been  passed  through  the  dies  once  it  is  reversed  as 
stated,  and  then  fed  through  against  another  set  of  stops  so  that  the  blank 
stock  left  between  the  openings  punched  in  the  original  passage  through 
the  dies,  is  pierced  and  a  second  row  of  blanks  cut  out.  This  is  indicated 


STYRIAN  TOOL  STEEL- 

4.&0  Fllisterhead  Screws. 


Screws,  %*long.. 


?%  Donets     ' 
FIG.  377.  —  Piercing  and  blanking  die 

by  the  dotted  lines  in  the  plan  view,  Fig.  377,  which  shows  the  manner  in 
which  the  stock  is  stopped  against  the  spring  plug  in  its  second  run  through 
the  press. 

THE  BENDING  TOOLS 

The  bending  or  forming  tools  are  seen  in  position  in  Fig.  378.  They 
consist  of  a  simple  punch  and  a  die  with  a  gap  of  the  right  width  to  bend  up 
the  ears  on  the  opposite  sides  of  the  blank,  and  a  suitable  nesting  pin  over 
which  the  blank  is  located  properly  before  the  punch  descends.  The  die 
carries  a  shedder  which  is  forced  down  against  the  spring  action  to  allow 
the  blank  to  be  bent  up  on  opposite  sides.  Upon  the  up  stroke  of  the 


BENDING  AND  FORMING  DIES  271 

press,  this  shedder  forces  the  formed  work  upward  and  out  of  the  tools. 
The  margin  stops  are  then  ready  for  the  piercing  operation  performed  by 
the  tools  illustrated  in  Figs.  379  and  380. 

The  press  tools  for  the  final  piercing  are  illustrated  by  Fig.  380,  and  the 
construction  will  be  understood  upon  examination  of  Fig.  379.     It  should 


FIG.  378.  —  The  bending  tools 

be  noticed  that  the  purpose  of  these  tools  is  to  pierce  the  plain  side  of  the 
blank  exactly  in  line  with  the  hole  and  notch  punched  in  the  opposite  side 
in  the  first  operation  as  already  described. 

The  method  of  alining  these  holes  in  the  press  tools  is  shown  distinctly 
by  Fig.  380.  The  dies  are  made  right  and  left  hand,  and  perform  exactly 
the  same  work,  but  on  opposite  sides.  The  work  is  nested  on  the  punch. 
That  is,  the  bent  blank  with  the  holes  punched  in  one  side,  is  slipped  up  over 
the  punch  and  when  the  punch  and  work  descend  together,  a  leaf  on  the 
die,  which  is  shown  in  Fig.  379,  snaps  shut  and,  coming  between  the  upper 
and  lower  wings  on  the  formed  blank,  is  designed  to  serve  as  a  stripper  on 
the  upstroke  of  the  punch.  The  tools  shown  at  the  right  of  Fig.  380  repre- 
sent the  punch  in  its  lower  position  and  show  the  method  of  operating  this 
pivoted  stripper.  The  letters  on  the  drawing  will  enable  this  operation  to 
be  understood. 

As  the  punch  comes  down,  it  strikes  the  leaf  on  the  stripper,  which  is 
swung  into  place  between  the  two  wings  of  the  bent  blank.  In  this  po- 


272 


PUNCHES  AND  DIES 


"Drill 


FIG.  379.  —  Details  of  piercing  tools 


FIG.  380,  —  The  press  tools 


BENDING  AND  FORMING  DIES 


273 


sition  the  leaf  is  locked  shut  by  a  beveled-end  spring  plunger  lying  hori- 
zontally, which  snaps  outside  of  the  vertical  lever  on  the  side  and  slides 
along  up  this  upright  when  the  punch  ascends. 

This  arrangement  of  locking  mechanism  and  releasing  device  for  the 
stripper  is  illustrated  in  Fig.  380,  where  the  horizontal  spring  plunger  can 
be  seen  at  A,  while  the  lever  against  which  it  acts  and  rests  during  its  upper 


FIG.  381.  —  Bending  tools  for  a  spring 

stroke  is  at  B,  which  is  slightly  modified  from  the  construction  details 
shown  in  Fig.  379,  although  in  principle  remaining  the  same.  When  the 
punch  has  reached  the  top  of  its  stroke,  the  spring  plunger  is  out  of  contact 
with  the  lever.  The  latter  then  swings  outward,  allowing  the  stripper  to 
fly  open  so  as  completely  to  clear  the  work,  which  is  then  removed  from  the 
die  and  another  part  put  in  place  for  piercing.  This  arrangement  forms  a 
safety  device  for  the  die  and  punch;  for  if  the  stripper  were  to  swing  open 
during  contact  of  the  punch,  the  latter  or  some  part  of  the  die  might  be 
broken. 


274 


PUNCHES  AND   DIES 


BENDING  TOOLS  FOR  TYPEWRITER  SPRINGS 

The  tools  in  Fig.  381  are  for  bending  a  ribbon  reverse  detent  spring  for 
the  same  typewriter.  This  spring  is  shown  in  the  detail,  Fig.  382.  Fig. 
383  gives  a  plan  and  side  view  of  the  press  tools  for  the  work. 

The  material  is  tool  steel  0.020  in.  thick,  and  the  strip  stock  is  3|  in. 
wide.  Before  bending  the  spring  the  blank  is  punched  practically  the 
full  width  of  the  stock,  the  blanks  being  formed  crosswise  of  the  strip. 
The  character  of  the  blank  as  it  appears  before  bending  is  well  illustrated 

in  Fig.  381,  where  a  blank  and 
two  springs  are  seen  in  the 
foreground,  and  on  the  face 
of  the  die  a  blank  ready  for 
bending.  It  will  be  seen  from 
this  illustration  that  the  work 
is  nested  between  angular  guide 
plates  on  opposite  sides  of  the 
die  proper.  The  die  itself 
consists  of  two  movable  jaws, 
which  are  carried  in  a  longi- 
tudinal guide  in  the  die  block 
and  slide  toward  the  center 


Harden  and  Temper 


FIG.  382.  —  Detail  of  small  spring 


when  acted  upon  by  the  de- 
scent of  the  punch.  These 
jaws  are  clearly  shown  in  Fig.  383.  It  will  be  seen  upon  inspection  of  this 
illustration  that  the  rear  ends  of  the  jaws  are  finished  at  an  angle  of  45 
degrees  as  indicated  at  AA.  Similar  sloping  surfaces  are  provided  upon 
the  inner  faces  of  the  blocks  BB.  The  blocks  are  attached  to  the  punch 
carrier  above.  When  the  punch  comes  down,  the  members  BB  come- in 
contact  with  dies  AA  and  force  them  inward,  causing  the  blank  to  hug  the 
punch  closely.  As  a  result,  when  the  latter  forces  the  blank  down  through, 
the  work  is  pressed  tightly  against  the  sloping  sides  of  the  parts  in  contact 
with  it  and  the  V-shaped  spring  with  the  flaring  opening  at  the  top  is 
formed  at  one  stroke.  It  should  be  noted  that  the  open  end  of  the  spring 
is  finished  to  90  degrees  included  angle,  this  being  secured  by  the  angular 
lower  face  of  the  punch  indicated  at  C. 

The  partial  section  in  the  elevation  in  Fig.  383  shows  a  heavy  com- 
pression spring  at  D.  This  causes  the  punch,  after  it  has  reached  the 
bottom  of  the  die,  to  dwell  in  that  position  during  the  remainder  of  the 
downward  stroke,  while  the  operating  blocks  BB  are  carrying  the  jaws 
A  A  toward  the  center  to  form  the  spring  against  the  faces  of  the 
punch. 

On  the  upstroke  of  the  press  the  die  jaws  are  drawn  open  by  the  springs 


BENDING  AND  FORMING  DIES 


275 


shown  at  each  side.  The  formed  flat  spring  is  pulled  up  out  of  the  die 
with  the  punch.  From  this  member  it  is  removed  by  drawing  it  off  toward 
the  front  with  the  hand. 

FORMING  THE  RIBBON  CORE 

The  ribbon  core  for  the  typewriter  is  about  2f  in.  long  by  J  in.  in  width. 
The  material  is  0.020  in.  thick  and  of  the  same  width  as  the  finished  core. 
The  part  before  and  after  bending  is  shown  in  Fig.  384.  When  complete 


BiOTTOM  VIEW 
OF  PUNCH 


FIG.  383.  —  Spring  forming  tools 

it  is  formed  into  a  circular  ring  0.76  in.  in  diameter.  At  one  side  is  a  rect- 
angular recess  the  full  width  of  the  ring.  Just  below  the  recess  there  is  an 
arrow  shaped  projection,  produced  by  punching  a  V-slot  through  the 
metal,  leaving  a  tongue.  When  this  is  bent  out  from  the  periphery  of  the 
ring  it  forms  a  hook  upon  which  the  end  of  the  ribbon  is  secured  for  wind- 
ing upon  the  spools. 

The  press  tools  for  piercing,  forming  and  cutting  off  this  core  are  shown 
in  Fig.  385.  With  the  tools  in  this  position  the  stock  feeds  in  from  the 
left-hand  side,  although  when  set  up  in  the  press  this  open  side  for  the 


276 


PUNCHES  AND  DIES 


stock  guide  would  come  to  the  right.  The  strip  of  material  is  first  fed 
forward  until  a  shearing  punch  at  the  middle  cuts  off  the  end  squarely, 
after  which  the  stock  is  advanced  to  the  stop  at  the  extreme  right.  There- 
after a  core  is  bent  and  cut  off  at  each  stroke  of  the  press. 

The  parts  as  they  come  from  the  dies  appear  as  illustrated  in  the  fore- 
ground of  Fig.  385.  The  notching  punch,  which  cuts  the  opening  to  pro- 
duce the  tongue,  is  the  first  in  a 
series  of  punches  and  will  be  seen 
at  the  left  side  in  the  punch  block. 
The  next  operating  punch  is  the 
one  in  the  center,  which  acts  as  a 
shear  to  sever  the  work.  The 
rounded  punch  at  the  right,  with 
the  rectangular  groove  across  its 
face,  forms  the  work  with  a  semi- 
circular bottom  and  forms  up  the 
rectangular  depression  across  its 

face.   The  material  is  guided  under 
FIG.  384.  —  Detail  of  ribbon  core  , i       .   •  i   .         *** 

the  stripper  plate  and  between  pairs 

of  small  pins,  which  control  its  lateral  position  accurately.  This  arrange- 
ment of  tools  means  that  after  the  process  is  once  under  way  a  core  is 
being  formed  up  at  the  right  and  cut  at  the  same  stroke,  while  the  V-pierc- 
ing  punch  at  the  left  is  cutting  out  the  outline  for  a  tongue  for  the  next 
core.  On  the  next  stroke  of  the  press,  the  work  is  advanced  again  to  the 
stop,  this  second  piece  is  formed  up  and  cut  off  while  the  third  tongue  is 
cut  out  in  the  stock.  When  the  blanks  leave  the  press,  they  are  in  a  U 
form.  They  are  bent  to  a  complete  circle  by  another  set  of  tools  not  shown 
here.  The  ends  of  the  work  overlap  in  the  finished  ring  about  J  in.  and  are 
joined  under  an  electric  welder  while  held  on  special  fixtures. 

DIES  FOR  CALCULATING  MACHINE  PARTS 

The  views,  Figs.  386  to  402,  illustrate  some  of  the  press  tools  for  manu- 
facturing parts  for  the  Marchant  calculating  machine,  various  other  dies 
for  which  are  shown  at  different  places  in  this  treatise. 

The  group  of  parts  in  Fig.  386  represent  the  stages  in  the  development  of 
a  cover  for  the  carriage  of  this  machine,  from  the  plain  steel  blank,  to  the 
formed,  trimmed,  and  finished  article.  In  this  view  the  sequence  is  as  fol- 
lows: A  shows  the  blank;  B  the  blank  with  the  long  end  pierced;  C  the 
blank  with  both  ends  pierced;  D  the  stamping  of  the  numerals  on  the  long 
end;  E  the  stamping  complete;  F  the  forming  of  the  cover  to  shape; 
G  the  embossing  of  the  bend  along  the  long  row  of  square  openings;  H 
the  cover  trimmed  to  width  and  thus  completed. 

Details  of  the  blank  are  given  in  the  line  drawing,  Fig.  387,  and  the 


BENDING  AND  FORMING  DIES 


277 


FIG.  385.  —  Bending  tools  for  ribbon  cores 


'. 


u 


F 


H 


FIG.  386.  —  Operation  in  making  a  calculating  machine  cover  plate 


278 


PUNCHES  AND  DIES 


piece  complete  is  shown  by  Fig.  388.  Fig.  387  shows  the  cover  to  be  9.215 
in.  long  over  all,  and  the  blank  width  to  be  Ijf  in.  The  stock  is  0.040  by 
2  in.  cold  rolled  steel.  There  are  18  rectangular  holes  pierced  from  one  end 
and  10  square  holes  from  the  other.  After  the  area  enclosing  the  row  of  18 
openings  has  been  embossed  (following  the  forming  operations)  the  holes 
appear  as  in  the  drawing,  Fig.  388. 


Cut  Bevels  .40 

•™            Form    9/16 

Had.    1/16    Deep 

j,            X  jX* 

/ 

'«BQQQQQoQQQ    C 

DDDDDDDDDDDDDDDDC 

4  '  

Flatten  Sections  .010  before 
Milling  Bevels.    Openings  to 
Measure  .185  long  after  Forming 

Sight  Openings  to  Measure    .300  after  Forming 

FIG.  3  88 

End  View  of  Form 
itaqd.  to  Fit  Carriage 
after  Cuttiug-off 
Strip  .508  to  .510  Wide 

I              '                *  ! 

*  42  Holes 

_H*|"^135 

f            ^4- 

X  10   9     876     54     321 

Epaddapnapp 

\s|   '         t 

]ir!i    2r  ' 

iFl 

JS  /       1 

UDDDDDQDDDDDDDDDi: 

10  Blots  Spaced  .275 


18  Slots  Spaced  .275 


FIG.  3  87 
FIGS.  387-388.  —  Detail  of  cover  plate 

THE  BLANKING  TOOLS 

The  first  and  second  operation  dies,  for  blanking  and  piercing  re- 
spectively, are  shown  in  operation  in  the  press,  in  Figs.  389  and  390. 
The  blanking  tools  are  seen  in  detail  in  Figs.  391  and  392,  the  latter 
engraving  including  the  general  dimensions  of  the  punch  and  die. 

The  die,  it  will  be  noticed,  is  of  sectional  construction,  in  which  four 
separate  die  blocks  are  put  together,  two  for  each  side  9.215  in.  long,  and 
two  for  each  end  4T7^-  in.  long.  The  die  sections  are  all  1-ft  in.  wide  and 
1  in.  deep.  They  are  of  tool  steel,  hardened,  and  ground  accurately  to  di- 
mensions. The  long  sections  are  secured  by  four  f-in.  fillister  head  screws 
and  three  dowels  of  the  same  diameter;  the  short  end  sections  are  similarly 
held  to  the  base  by  two  screws  of  the  same  size  and  two  dowel  pins. 

The  inner  edges  of  the  die  sections  are  all  ground  to  the  usual  clearance 
of  J-degree  taper.  The  method  of  construction  enables  the  die  blocks  to 
be  hardened  and  then  ground  to  size  to  assure  accuracy  in  all  respects. 
Also,  it  permits  the  sections  to  be  corrected  for  wear  by  grinding  the  con- 
tact faces  and  setting  up  if  at  any  time  this  becomes  necessary. 

The  punch  is  made  up  of  a  single  block  of  tool  steel  hardened  and 
ground  to  dimensions  with  all  edges  square  and  parallel.  It  is  fastened  to 
its  holder  by  means  of  four  f-in.  fillister  head  screws  and  two  dowel  pins. 


BENDING  AND  FORMING  DIES 


279 


The  stripper  is  a  machine  steel  plate  which  is  seen  clearly  in  the  photo- 
graph, Fig.  391,  and  in  the  front  elevation,  Fig.  392.  It  is  made  with  an 
opening  J  in.  longer  and  wider  than  the  die  opening  to  give  a  clearance 
space  TV  in.  wide  all  around  the  punch  when  the  latter  descends.  The 


FIG.  389.  —  Blanking  dies  in  operation 

stripper  is  |  in.  thick  and  is  mounted  on  guide  strips  -fa  in.  thick  to  allow 
the  stock  to  pass  through  readily.  The  left 'end  of  the  opening  in  the 
stripper  is  milled  out  to  provide  a  J-in.  opening  over  the  stock  which  will 
be  noticed  in  the  photograph,  Fig.  391.  This  stop  is  low  enough  to  allow 
the  strip  of  material  to  be  lifted  and  passed  along  to  successive  positions 
without  difficulty  during  the  operation  of  the  press.  The  appearance  of 
the  scrap  strip  after  leaving  the  dies  is  shown  by  the  photograph  of  the  set- 
up in  Fig.  389. 


280 


PUNCHES  AND  DIES 


FIG.  390.  —  Piercing  dies  in  the  press 


FIG.  391,  —  The  blanking  die 


BENDING  AND  FORMING  DIES 


281 


PIERCING  THE  EIGHTEEN  HOLES 

The  piercing  operation  in  Fig.  390  is  the  punching  of  the  18  rectangular 
holes  in  the  long  end  of  the  blank.  This  work  is  also  accomplished  with 
dies  of  sectional  type.  The  tools  are  shown  in  Fig.  393  with  a  sample  of 
the  work  in  front,  and  in  Fig.  394  all  details  of  construction  are  covered. 


L.j    i  Vtj          !   i         !,.-;          i    i        ir-ri         |   ! 

^J  i    !T"-y    1  -  Stripper 

rprfl 

U.i 

i         !  '          ii 

i      --!      '  ' 

3  p 

fe        i     t-H                  ! 

i    !  IS         j 

1 

/  1                ITd                                           C-d' 

!        E=3            !         ^ 

F""i               '     '               F"-| 

ft    ' 

,J--l    1  ,J--l                        ]-J,                       J--1                       ^—  il 
!              !  n  i     1   '  -  !                           !-i                          I-;                          !„! 

MJ 

l 

FIG.  392.  —  Construction  of  sectional  blanking  die 

The  holes  pierced  are  known  as  " sight  openings"  as  they  enable  the  dial 
readings  to  be  observed  through  the  carriage  cover  when  the  calculating 
machine  is  in  operation. 

The  blank  rests  for  the  piercing  operation  against  a  long  back  stop  on 
the  die  and  an  end  stop  for  the  left  end  of  the  blank.  The  blank  is  pressed 
back  against  the  rear  stop  surface  by  a  spring  actuated  plunger  shown  at 


282 


PUNCHES  AND  DIES 


FIG.  393.  —  Piercing  tools  for  long  end 


17  Sections  Center  .073 

Bight  Openings-.2CO  'i  .£C5' 

Space  =275'each  Section 


lls  1  Long        Scws.-l  ^'long.Dowells  1  j^ 

Punch  17  Reqd.  (  Make  22 )         Die  Section  17  Reqd.  (Make  22) 
Paragon  Steel  Paragon  Steel 

Pierceing  Die  Sight  Openings 
Product  Dials  &  Carriage  Covers 
R-54  &  F-7 


FIG,  394,  —  Slot  piercing  die.    Sectional  construction 


BENDING  AND  FORMING  DIES  283 

the  front  of  the  die.  The  punch  head  carries  a  pressure  pad  and  stripper 
through  which  the  Individual  punches  are  closely  fitted.  This  stripper  is 
actuated  by  stiff  pressure  springs,  four  in  front  and  four  in  back,  which  are 
coiled  from  J-in.  square  steel.  The  stripper  is  connected  with  the  punch 
holder  or  head  by  eight  yVin-  fillister  head  screws  adapted  to  slide  up 
through  the  counterbored  seats  in  the  holder  when  the  latter  descends  upon 
the  work. 

THE  DIE  SECTIONS 

The  die  base  and  punch  holder  are  cast  to  the  form  shown  in  the  draw- 
ing. The  die  base  is  planed  out  lengthwise  to  provide  a  channel  in  its 
face  2.507  in.  wide  by  f  in.  deep  for  the  reception  of  the  die  sections  A,  of 
which  there  are  17  in  all.  The  die  sections  are  made  0.275  in.  wide  by  J 
in.  deep  and  are  2.507  in.  long  to  fit  the  seat  planed  in  the  base.  The  die 
section  is  made  with  half  the  width  of  opening  in  each  side  as  at  B,  and  the 
long  dimension  of  the  opening  is  0.307,  or  two  thousandths  more  than  the 
width  of  the  punch  for  clearance.  The  punch  is,  of  course,  0.305  in.  the 
same  as  the  slot  required  in  the  blank. 

With  the  die  section  made  symmetrical  as  shown,  there  is  less  likelihood 
of  its  springing  when  hardened  and  it  is  in  some  respects  easier  to  construct 
in  the  first  place  as  the  depth  of  cut  on  each  side  for  grinding  is  only  half 
what  it  would  be  if  the  opening  were  all  from  one  side. 

There  are  two  8  X  32  thread  screw  holes  in  each  section  and  two  Jrin. 
holes  for  dowel  pins.  The  sections  are  all  ground  on  the  sides  to  bring 
them  to  the  uniform  width  of  0.275  in.,  and  the  cutting  portion  at  B  is 
ground  \  degree  taper  for  clearance  for  the  passage  of  the  slugs  punched 
out  in  operation. 

At  each  end  of  the  series  of  17  die  sections  A,  there  is  a  wider  block 
C  (measuring  1J  in.)  to  secure  all  in  place.  At  the  back  there  is  a  guide 
plate  of  machine  steel  which  overlaps  the  ends  of  the  die  sections  as  at  D. 
In  front  is  located  the  dovetailed  slide  E  which  is  forced  forward  by  £he 
flat  spring  F  to  keep  the  work  in  contact  with  the  guide  at  the  rear. 

THE  PUNCHES 

The  individual  punches  are  made  in  the  form  represented  at  G.  They 
are  of  tool  steel,  hardened  and  provided  with  a  T-shaped  head  ground  to -a 
thickness  of  0.275  in.  and  in  this  case  the  punch  proper  is  flush  with  one 
face  of  the  head  so  that  by  placing  the  punch  flat  on  the  magnetic  chuck  the 
opposite  face  may  be  readily  ground  to  thickness.  The  same  size  of 
screws  and  dowels  is  used  here  as  for  the  die  sections.  The  appearance  of 
the  series  of  punches  when  assembled  on  the  head  is  shown  by  the  front 
elevation  in  this  drawing. 

The  punch  head  and  die  base  are  provided  with  1-in.  guide  pins  for 
aligning  the  tools,  thus  giving  them  the  sub-press  type  of  action. 


284 


PUNCHES  AND   DIES 


If* 

' '  (v 


bfl 


BENDING  AND  FORMING  DIES 


285 


The  second  piercing  operation,  Fig.  395,  punches  the  shorter  row  of 
holes  in  the  opposite  end  of  the  blank.  The  tools  are  shown  removed  from 
the  press  in  Fig.  398.  The  work  is  located  on  the  die  base  by  a  square  stop 


FIG.  398.  —  Piercing  tools  for  short  end 


,» 


FIG.  399.  —  Stamping  tools  for  marking  numerals 

pin  which  enters  the  last  hole  in  the  long  row  already  pierced  and  so  the 
position  is  accurately  fixed  in  relation  to  this  first  series  of  openings.  The 
back  of  the  work  rests  against  the  guide  strip  at  the  rear  of  the  die,  and  it 
is  pressed  lightly  but  securely  against  the  guide  by  a  spring  plunger  which 
bears  against  the  front  edge  of  the  blank. 


286 


PUNCHES  AND  DIES 


STAMPING,  FORMING,  AND  EMBOSSING 

The  stamping  of  the  face  of  the  blank  with  the  numerals  opposite  the 
two  sets  of  openings  is  accomplished  with  the  dies  in  Fig.  399.  The  two 
series  of  stamps  are  used  separately  in  a  holder  like  that  shown  to  the  right 
in  the  engraving.  The  die  is  a  flat  steel  plate  on  a  cast  base,  with  an  ad- 


FIG.  400.  —  The  forming  dies 


FIG.  401.  —  The  embossing  die 

justable  stop  rod  at  the  front  which  is  set  by  turning  it  in  its  seat  to  swing 
the  pin  A  out  of  the  notch  in  the  die  plate  and  allow  it  to  enter  the  desired 
stop  opening.  This  rod  has  a  gage  arm  at  the  right-hand  end  which  car- 
ries a  screw  point  for  adjustment  to  close  settings  endwise.  The  work  rests 
against  the  guide  plate  at  the  back  of  the  die  with  its  end  located  against 
the  stop  screw  referred  to. 


BENDING  AND  FORMING  DIES 


287 


The  steel  stamps  for  forming  the  numerals  in  the  work  are  adapted  to 
be  slipped  into  the  punch  holder  and  there  secui'ed  by  the  series  of  screws 
at  the  front,  and  the  small  end  binding  screw  at  the  right. 

The  forming  dies,  Figs.  396  and  400,  bend  the  blank  up  lengthwise  to 
an  angle  of  115  degrees  included.  These  dies  are  simple  forming  tools 
which  require  no  description.  The 
work  passes  from  this  operation  to 
the  embossing  dies,  Fig.  401,  where 
the  surface  M  (Fig.  387)  is  de- 
pressed as  at  N  to  form  a  concave 
portion  extended  to  include  all  of 
the  cross  bars  of  metal  left  be- 
tween the  square  holes  by  the 
piercing  tools.  This  effect  is 
clearly  shown  in  Fig.  401.  A 
section  through  the  dies  is  repro- 
duced in  Fig.  402.  This  shows 
that  the  embossing  punch  A  is 
provided  with  a  heavy  pressure 
pad  controlled  by  ten  J-in.  springs 
for  holding  the  work  in  the  die  n°-  402.  -  Section  of  embossing  dies 

seat  B  while  the  formed  edge  is  concaved  to  the  form  at  C.  The  oppo- 
site end  of  these  dies  is  made  to  flatten  the  surface  along  the  short  series 
of  holes  at  the  other  end  of  the  work.  Afterward,  the  bevel  edges  at  X 
(Fig.  388)  are  produced  by  a  milling  process. 


10  Springs 
Vl"  Dia. 
Pressure 
Padx 


FIG.  403.  —  The  trimming  tools 

The  final  operation  in  the  press  tools  is  shown  by  Fig.  397,  this  being  the 
trimming  of  the  edge  to  a  definite  distance  from  the  sighting  holes.  The 
tools  for  this  are  also  shown  in  Fig.  403.  The  method  of  holding  the  work 
on  the  fixture  (for  the  die  is  in  the  form  of  a  tool  of  this  character)  is 
shown  by  Fig.  397  where  the  formed  cover  plate  is  seen  resting  upon  a 


288 


PUNCHES  AND  DIES 


locating  ledge  on  the  face  of  the  device  while  two  knurled  head  screws  are 
used  for  clamping  the  work  in  place.  In  this  position  the  projecting  edge 
of  the  piece  will  be  trimmed  to  the  exact  width  required.  The  cover  before 
and  after  trimming  is  shown  in  Fig.  403. 

The  punch  or  upper  trimming  tool  is  sheared  lengthwise  about  T*B  in. 
in  the  length  of  10  in.  and  also  has  a  side  clearance  of  about  5  degrees, 
both  being  to  assure  free  cutting  action  and  smooth  edged  results. 

DRAWING  AND  FORMING  A  FOUR-SIDED  COVER 

The  illustrations  that  follow  relate  to  the  manufacture  of  another 
form  of  mechanism  cover  for  the  same  make  of  calculating  machine.  The 
production  of  this  article  involves  the  application  of  the  processes  of  blank- 


FIG.  404.  —  Sequence  of  operation  on  a  small  machine  cover 

ing,  drawing,  trimming,  piercing,  and  forming  in  press  tools,  and  the  taking 
of  one  cut  in  a  milling  machine.  The  sequence  of  operations  is  repre- 
sented by  the  group  photograph,  Fig.  404,  which  shows  the  work  from  the 
blank  to  the  finished  cover.  In  this  view,  A  shows  the  blank;  B  the  first 
draw;  C  the  second  draw;  D  the  piece  burnished ;  E  the  bottom  and  ends 
milled  off  with  a  cutter;  F  the  ends  trimmed;  G  the  finger  hole  and  slots 
pierced;  H  the  completed  cover  with  ends  bent  to  shape. 

Details  of  the  cover  are  given  in  the  drawing,  Fig.  405,  and  the  operation 
schedule  is  included  in  this  engraving.  The  piece  is  made  from  0.040-in. 
brass  stock. 

The  blank  is  made  with  dies  of  simple  sectional  construction,  the  die 
itself  being  constructed  in  halves.  This  die  is  shown  in  Fig.  75  in  Chap- 
ter II  and  need  not  be  reproduced  here.  It  makes  a  blank  similar  to  A, 


BENDING  AND  FORMING  DIES 


289 


Fig.  404,  which  is  of  elliptical  form  with  a  length  of  5J  in.  and  a  width  of 
3  in.  The  operations  that  follow  give  a  good  opportunity  to  study  the 
evolution  of  a  blank  of  this  contour  through  the  successive  shapes  it  as- 
sumes until  it  is  completed. 


1st    Operation  =  Blank 


2nd 
3rd 
4th 
5th 


7th 
8th 
9th 


=  No.l  Draw 

=  No.2  Draw 

=  Burnish 

=  Trim      Ends 

—  Mill  Bottom  &  Top  Edges 

Off 
=  Pierce  Slots 

=.  Pierce  Finger  Tip    Holes 
=  Form  Ends 

3/32  Rad.Iiisido 


-\  A  k 

I    I 

sU 


II  I       //, 

- — 3.(C2  Inside »- >|  X  K— 

! 


t« 

S  3 


n 


Bad. 


Slot    K  x  5/ic  Lower  Edge  81/82  From  Base 


No.  42  Holes 
|   Csk  for  2 

Diam. 


1 

- 

- 

1=1 

[-1 

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\ 

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, 

iL 


FIG.  405.  —  Detail  of  carriage  cover  for  calculating  machine 

THE  DRAWING  OPERATIONS 

The  first  drawing  operation  is  accomplished  with  the  dies  in  Fig.  406. 
In  this  case  the  die  proper  B  is  the  upper  member  of  the  set  and  the  punch 
B'  is  carried  by  the  cast-iron  base  to  which  it  is  attached  by  fillister  head 
screws  and  dowels,  let  in  from  the  under  side  of  the  shoe.  A  drawing  pad 
or  pressure  pad  B"  is  provided  which  fits  over  the  drawing  post  or  punch 
B',  and  this  is  acted  upon  by  pressure  pins  which  extend  down  through  the 
base  and  rest  upon  a  spring  plate  C,  which  receives  the  upward  thrust  of 
the  long  coiled  spring  which,  when  assembled  in  working  position,  is 
secured  to  the  base  by  the  threaded  rod  shown,  this  being  passed  through 
the  center  of  plate  C  and  screwed  into  a  tapped  hole  in  the  base. 

This  first  drawing  operation  produces  a  piece  drawn  in  at  an  angle  of 
about  110  degrees  (to  correspond  with  the  included  angle  at  the  closed  side 
of  the  cover  at  a,  Fig.  405)  and  to  a  depth  of  about  |  in.  The  second 
drawing  operation  with  the  tools,  Fig.  407,  draws  the  box  form  to  depth 
as  shown  by  the  work  at  the  front  of  the  dies.  These  tools  are  in  general 
similar  in  construction  to  those  for  the  first  draw  and  they  use,  in  fact, 


290 


PUNCHES  AND  DIES 


FIG.  406.  —  First  operation  drawing  die 


FIG.  407.  —  Tools  for  second  draw 


FIG.  408.  —  "Push  through"  dies  for  third  draw 


BENDING  AND  FORMING  DIES 


291 


the  same  pressure  plate  and  spring  below  the  drawing  post  base.  The 
die,  however,  is  provided  with  a  spring  knock  out.  Both  drawing  opera- 
tions leave  the  work  with  flared  out  ends  which  indicate  the  manner  in 
which  the  stock  is  held  between  the  drawing  surfaces  to  prevent  wrinkling 
of  the  work. 

The  next  operation  is  in  the  dies,  Fig.  408,  where  a  "push  through" 
construction  is  used,  these  dies  straightening  out  the  sides  of  the  work  and 
having  a  burnishing  effect  upon  the  walls. 

It  should  be  noted  that  all  of  these  drawing  dies  have  a  liberal  radius 
for  the  corners  to  allow  the  metal  to  flow  into  the  die  without  breaking, 
and  the  spring  tension  is  regulated  to  give  the  desired  gripping  pressure 
on  the  work  between  the  opposing  surfaces  so  that  wrinkles  are  avoided. 


FIG.  409.  —  Trimming  dies 

THE  TRIMMING  OF  THE  ENDS 

The  trimming  of  the  ends  in  the  following  operation  is  done  with  the 
tools  in  Fig.  409.  These  dies  are  of  novel  design.  They  are  arranged  to 
receive  the  drawn  cover  which  is  slipped  vertically  over  the  die  proper  and 
which  is  then  cut  out  at  the  edge  by  the  trimming  punches  to  form  a  con- 
caved opening  or  notch  at  that  point.  The  dies  are  double,  right  and 
left  hand,  and  the  work  is  first  trimmed  at  one  end  over  one  of  the  dies, 
then  placed  the  other  end  up  on  the  other  die  for  the  trimming  at  the  second 
end. 

The  shape  of  the  notch  cut  out  by  the  trimming  tools  is  indicated  at  b, 
Fig.  405,  although  the  full  depth  is  not  here  represented  as  the  drawing 
shows  the  cover  in  completed  form  after  a  milling  operation  has  been  at- 
tended to. 

The  trimming  dies,  Fig.  409,  are  made  up  of  machine  steel  blocks  E 
to  which  are  secured  hardened  tool  steel  die  sections  F  which  are  seated 


292 


PUNCHES  AND   DIES 


against  the  main  block  and  secured  by  fillister  head  screws  and  dowel  pins. 
The  blocks  E  are  cut  away  at  the  bottom  to  admit  the  lower  edges  of  the 
work  which  is  slipped  over  blocks  E  in  upright  position,  with  the  bottom 
ends  extending  into  the  clearance  slots  referred  to.  The  die  cutting  edges 
are  backed  up  by  a  rubber  pad,  or  buffer  G  which  strips  the  scrap  edge 
after  the  trimming  punch  rises.  The  latter  is  made  in  sections  for  con- 
venience and  each  section  is  secured  to  the  punch  holder,  as  plainly  indi- 
cated, by  screws  and  dowel  pins. 

A  sketch  of  the  general  construction  of  the  dies  is  given  in  Fig.  410 
showing  the  method  of  holding  the  work  by  slipping  it  over  the  main  block 


FIG.  410.  —  Section  through  trimming  die 

and  resting  it  on  the  die  sections  at  the  top.     The  guide  posts  for  alining 
the  punch  holder  and  die  base  are  also  indicated  here. 

Following  the  trimming  in  these  dies,  the  surplus  metal  along  the  long 
edge  of  the  cover  is  trimmed  off  in  a  milling  fixture  with  a  cut  similar  to 
that  indicated  at  E}  Fig.  404.  Then  two  piercing  operations  are  performed. 

THE  PIERCING  AND  FORMING  TOOLS 

The  tools  for  the  first  piercing  operation  are  shown  to  the  right  in 
Fig.  411;  these  pierce  the  four  slots  in  the  front  of  the  cover.  The  slots 
are  ^  in.  wide  by  f  in.  deep  and  they  are  spaced  apart  a  center  distance 
given  on  the  blueprint,  Fig.  405. 

The  photograph  of  these  slot  piercing  dies  is  self-explanatory.  The 
dies  are  of  the  sub-pressed  order,  with  stiff  guide  pins  at  the  rear  of  die  shoe 


BENDING  AND  FORMING  DIES 


293 


and  punch  head.  The  die  blocks  are  fitted  together  sectional  fashion  with 
the  correct  gap  between  sections.  The  punch  is  similarly  built  up  with 
separate  sections  each  made  with  a  square  base  for  securing  to  the  holder 
with  screws  and  dowels.  The  punch  holder  carries  a  pressure  pad  and 
stripper  the  springs  for  which  are  better  seen  in  the  second  view  of  the 
same  tools  in  Fig.  412. 


;  FIG.  411.  —  Piercing  dies  for  finger  hole 


Forming  die 


FIG.  412 


Finger  hole  die 


The  piercing  tools  for  the  small  square  hole  in  the  top  and  front  corner 
of  the  work  are  shown  at  the  left  in  Fig.  411.  The  punch  is  a  simple  tool 
with  squared  cutting  portion  milled  on  the  end  of  a  round  shank  and  the 
stripper  is  a  bent  plate  secured  at  the  back  of  the  die  block  and  projecting 
forward  to  the  corner  of  the  die.  The  work  slips  under  the  open  end  of 
the  stripper. 

The  forming  tools  at  the  left  in  Fig.  412  bend  up  the  curved  ears  at  the 


294 


PUNCHES  AND  DIES 


ends  of  the  cover  to  a  width  of  J  in.  The  die  block  G  for  the  forming  of 
these  ears  is  shaped  for  the  curve  at  H  which  is  a  projection  across  the  face 
of  the  form  block.  The  block  G  rests  upon  a  narrow  support  below  and  its 
width  is  enough  less  than  the  distance  between  the  uprights  K  of  the  base 
to  provide  a  clearance  slot  to  admit  the  edges  of  the  cover  to  be  formed. 
The  projecting  ears  on  the  cover  rest  on  the  top  face  of  ledge  H.  Two 


FIG.  413.  —  Underside  of  coin  changer  back 

pieces  are  inserted  at  once,  one  from  each  side  of  the  die  block  G.  The 
punch  then  forms  the  ears  down  into  the  curved  fillet  at  the  bottom  of 
block  H. 

COIN  REGISTER  DIES 

The  dies  in  the  following  illustrations  are  a  few  of  an  extended  line  of 
similar  tools  used  for  making  various  parts  of  the  American  Coin'Register. 
There  are  in^connection  with  this  work  many  interesting  problems  in  the 
bending  and  forming  of  different  pieces,  and  one  part  requiring  some  well- 
designed  tools  for  such  purpose  is  illustrated  by  Figs.  413  and  414.  This 
is  a  sheet  steel  member  known  as  a  coin  changer,  which  is  manufactured  by 
a  sequence  of  press  operations. 

The  stock  is  0.062  in.  thick.  It  is  cut  off  under  the  shear  to  approxi- 
mate length  and  is  then  trimmed  and  pierced  in  the  first  operation  dies, 
Fig.  415  and  416.  The  pierced  blank  then  appears  as  in  Fig.  417.  The 
dies  are  so  clearly  shown  by  the  half  tone  and  line  drawing  as  to  need  little 


BENDING  AND  FORMING  DIES 


295 


in  the  way  of  description.     A  few  features  may,  however,  be  referred  to 
briefly. 

The  sheet  metal  plate  locates  against  gage  pins  A,  A,  A,  Fig.  416,  and 


FIG.  414.  —  Top  side  of  coin  changer  back 


FIG.  415.  —  End  blanking  and  piercing  dies 

when  the  punch  plate  descends  with  the  end  trimming  and  piercing  tools, 
the  pressure  pad  P  holds  the  plate  securely  and  acts  as  a  stripper  when  the 
punch  ascends.  The  punch  plate  carries  one  bending  punch  C"  which 
forms  up  the  lip  at  B.  This  punch  has  three  cutting  edges  to  outline  the 


296 


PUNCHES  AND  DIES 


SECTION  a-b 


FIG.  416.  —  End-trimming  and  piercing  tools  for  first  operation 


BENDING  AND  FORMING  DIES 


297 


FIRST  OPERATION 
TRIMMING  END  A  AND 
PIERCING  HOLES  AND  FORMING  TONGUE  R 


-*  *-^ 


SECOND  OPERATION 
PIEflCING  HOLES  C--DAND 
UP  LIP  L  AT  END 

FIG. 41 8 
FIGS.  417  and  418 


FIG.  419.  —  Tools  for  forming  flange  at  end  of  work 


298 


PUNCHES  AND   DIES 


tongue  of  metal  or  lip  C,  but  the  back  face  is  narrower  than  the  die  opening 
so  that  the  effect  is  to  cut  the  outline  of  C  around  the  three  corners  and 
then  fold  it  down  into  the  opening  in  the  die  as  shown  by  the  sectional 
sketch  at  the  side  of  the  drawing,  Fig.  416. 

The  large  holes  pierced  in  this  die  are  if  in.  diameter.  The  small  holes 
are  •/$  in.  The  piercing  punches  are  set  into  the  plate  D  and  the  latter  is 
secured  to  the  punch  holder  by  a  number  of  fillister  head  screws  and  dowel 


—6*4 

FORMING  AND  PIER.CING  TOOLS  FOR  SECOND  OPERATfQN 
FIG.  420 

pins.  The  small  piercing  dies  are  of  the  bushing  type  and  readily  replaced 
if  required.  The  end  trimming  is  done  by  tools  E,  carried  by  the  punch 
head,  and  F  secured  to  the  die  shoe.  These  tools  are  really  on  the  com- 
pound order,  the  punch  section  F  of  tool  steel  being  bored  and  ground  out 
for  the  die  openings  for  the  large  pierced  holes.  Like  the  rest  of  the  dies 
in  the  series,  these  are  provided  with  guide  pins  at  the  corners  of  the  shoe 
and  holder. 


BENDING  AND  FORMING  DIES  299 

The  work  as  it  comes  from  these  dies  is  shown  at  Fig.  417.  Fig.  418 
illustrates  it  as  it  appears  after  the  next  operation  where  the  front  end  is 
formed  and  bent  up  to  the  round  cornered  lip  indicated  at  L. 

THE  END-FORMING  DIES 

The  dies  for  forming  this  shallow  flange  or  lip  are  shown  by  Figs.  419 
and  420.  Referring  to  the  latter  view  it  will  be  seen  that  the  tools  are 
also  used  sfor  punching  two  large  holes  which  are  respectively  if  and  1TV  in. 
in  diameter.  So  the  operation  is  again  of  the  combination  type.  The 
blank  rests  over  the  series  of  locating  pin  p  with  its  end  to  be  formed 
projecting  over  the  edge  of  the  die  at  d.  The  punch  section.  S  is  made  to 


a 


FIG.  421.  —  Forming  tools  for  changer  back' 

allow  just  the  thickness  of  the  material  between  its  inner  edge  and  the 
corresponding  face  d  of  the  lower  die  and  when  the  punch  descends  it  folds 
the  flange  down  over  d  and  forms  it  to  shape. 

The  clearance  hole  marked  on  the  die  is  to  admit  the  narrow  tongue 
formed  in  the  first  operation  and  thus  keep  it  free  from  the  action  of  the 
second  operation  tools. 

The  pressure  pad  and  its  springs  are  shown  clearly,  and  other  features 
of  importance  are  all  detailed  in  the  drawing. 

THE  FINAL  FORMING  TOOLS 

The  tools  in  Figs.  421  and  422  receive  the  lower  end  of  the  blank  which 
rests  upon  the  sloping  face  A  of  the  lower  die  with  its  end  against  stop 
shoulder  B.  Upon  the  upper  die  descending  the  pressure  pad  C  (which 
is  supported  upon  four  screws  and  four  pins  carried  in  guide  bushings) 
holds  the  work  and  the  continued  descent  of  the  punch  forces  the  work 
down  to  the  shape  of  the  seat  on  lower  die  A.  The  pressure  springs  are 
very  stiff  and  they  carry  the  forming  die  down  parallel  to  the  face  of  the 
lower  die  because  of  the  guide  formed  by  the  four  corner  pins  P.  At  the 
same  time  after  the  upper  die  has  reached  a  certain  point  in  its  travel, 
the  fixed  form  F  bends  the  other  end  of  the  work  down  over  the  back  of 
the  die  at  G  and  forms  this  portion  of  the  piece  to  shape. 


300 


PUNCHES  AND   DIES 


FIG.  422.  —  Forming  dies  —  third  operation 


BENDING  AND   FORMING  DIES 


301 


There  are  two  longitudinal  corrugations  in  the  work  as  shown  by  Fig. 
413  and  these  are  produced  by  the  embossing  surfaces  on  the  dies  at  H 
and  Hf  respectively.  These  grooves  extend  around  the  curved  back  as 
indicated  and  are  continued  around  the  corner  by  the  corresponding  sur- 
faces of  the  die  block  at  I  and  /'. 


FIG.  423.  —  Third  operation  —  bending  and  forming 

The  lower  die  is  built  up  of  the  tool  steel  wedge  shaped  section  S  which 
is  mounted  upon  a  taper  shoe  or  block  T  which  gives  the  desired  angle  of 
slope  or  15  degrees.  Both  parts  are  secured  to  the  die  base  proper  by  a 
number  of  fillister  head  screws  and  suitable  dowel  pins. 

THE  CASING  FOR  THE  COIN  CHANGER 

The  casing  for  the  coin  changer  is  bent  and  formed  with  the  tools  in 
Figs.  424  and  425.  The  casing  itself  is  seen  at  the  right  in  Fig.  425,  at  the 
side  of  the  second  operation  dies. 

This  part  is  made  from  steel  plate  blanked  and  pierced  in  the  com- 
pound tools  illustrated  by  Fig.  144,  Chapter  IV.  As  it  comes  from  this 
set  of  dies  it  is  .placed  in  the  first  operation  forming  tools,  at  the  right  in 
Fig.  424  where  the  ends  are  bent  up  to  a  sharp  corner  by  the  punch  lip  A 
which  forces  the  work  down  over  the  end  B  of  the  lower  die.  The  blank 
is  located  in  this  die  by  resting  with  one  end  against  a  stop  plate  at  B  and 
the  blanked  narrow  body  against  gage  strip  C.  Then  in  the  dies  at  the 
left  in  the  same  view,  the  wings  are  partly  formed  by  starting  the  bend  in 
angular  faced  die  Bf  and  this  is  completed  by  the  finish  dies,  Fig.  425, 


302 


PUNCHES  AND  DIES 


where  the  blank  is  located  by  two  of  its  pierced  holes  over  locating  plugs 
in  the  lower  die.  The  distance  W  between  the  die  jaws  is  the  width  to 
which  the  work  is  to  be  formed  and  the  punch  X  is  made  with  a  face  equal 
to  the  width  of  the  work  measured  inside.  This  punch  acts  against  a 
spring  stripper  in  the  die  and  when  the  punch  ascends  after  forming  up 
the  work  to  the  outlines  shown  here,  the  stripper  ejects  the  finished  article 
from  the  die. 


FIG.  424.  —  Forming  tools  for  coin  changer  casing 


x 


w 


FIG.  425.  —  Finish  forming  tools  for  coin  changer  casing 

SIDE  CLOSING  DIES 

One  more  die  will  be  illustrated  here.  This  is  for  the  same  coin  register 
as  the  tools  just  described.  It  is  for  forming  up  a  steel  cover  like  that  shown 
in  the  background  of  Fig.  426.  The  work  measures  in  the  blank  7.865  in. 
wide  and  its  ends  are  bent  to  lengths  of  21 f  and  3 1 £  in.  respectively.  There 
is  a  large  radius  formed  in  each  corner  by  the  bending  tools  and  it  is  re- 
quired that  the  side  walls  be  parallel  with  one  another  when  the  piece 


BENDING  AND  FORMING  DIES 


303 


comes  from  the  dies.  As  there  is  a  certain  amount  of  spring  to  the  material 
this  is  compensated  for  by  forming  the  work  with  dies  that  are  under  cut 
to  allow  the  work  to  be  bent  past  the  vertical  line  the  necessary  amount 
to  give  right  angle  bends  when  the  article  has  been  allowed  to  spring  back 
after  leaving  the  dies.  The  small  openings  pierced  in  the  blank  are  made 
at  the  time  the  blank  is  cut  out,  a  combination  die  being  used  for  this  first 
operation. 

The  forming  dies  are  shown  by  Fig.  426.     The  punch  or  upper  die  is 
made  with  its  sides  sloping  inward  about  |  in.     At  each  end  of  the  punch 


FIG.  426.  —  A  side  closing  die 

holder  there  are  a  pair  of  taper  plungers  A  that  are  adapted  to  enter  slots 
in  the  sliding  jaw  bars  B  when  the  punch  holder  comes  down.  The  sliding 
members  are  normally  held  outward  by  compression  springs  between  them 
and  posts  C,  but  when  the  work  is  forced  down  against  pressure  pad  E 
and  the  plungers  A  enter  the  slots  in  B  the  latter  members  with  their 
jaws  move  toward  the  center  and  fold  the  work  up  to  the  inwardly  sloping 
sides  of  the  punch.  When  the  punch  ascends  again,  the  pressure  pad  rises 
and  the  closing  die  jaws  expand  under  the  action  of  the  springs  referred 
to.  The  slope  of  the  punch  sides  is  determined  by  trial  and  for  the  par- 
ticular size  of  work  shown  it  is  found  that  f  in.  is  sufficient  to  allow  the 
formed  work  to  come  from  the  dies  with  its  walls  standing  vertically. 


CHAPTER  XII 
DIES  FOR  EMBOSSING,   MARKING,   RIVETING,   SWAGING 

Several  ratchets  of  the  kind  used  on  the  platen  of  a  typewriter  are 
shown  in  the  foreground  of  Fig.  427.  They  are  about  1J  in.  outside 
diameter  by  f  in.  thick,  with  a  long  hub  and  a  j-in.  hole  bored  through. 
The  hub  fits  over  the  spindle  of  the  rubber  platen.  The  blanks  for  these 
ratchets  are  made  in  the  automatic  screw  machine.  The  form  in  which 
they  come  from  the  machine  is  seen  at  A  and  B,  Fig.  427,  where  two  ratchets 


FIG.  427.  —  Press  tools  for  typewriter  platen  ratchets 

are  shown  from  opposite  sides.  These  blanks  are  coated  with  copper.  A 
second  machining  operation  consists  in  forming  the  serrations  around  the 
edge  with  the  press  tools  shown  at  A  and  B  at  the  left  of  the  group  of 
tools  in  Fig.  427.  Then  the  serrations  are  shaved  with  the  tools  at  C 
and  D  at  the  right.  These  tools  consist  of  a  shallow  shaving  die  and  of  a 
punch  that  is  adapted  to  act  also  as  a  nest  for  the  blank.  The  pilot  on  this 
punch  has  a  slot  cut  crosswise  of  the  body  with  a  spring  projecting  at  either 
side  and  serving  to  retain  the  work  in  place  when  it  is  slipped  over  the  pilot. 

304 


DIES  FOR  EMBOSSING,   MARKING,   RIVETING,   SWAGING       305 


There  is  at  one  side  of  the  punch  a  locating  stop  E,  which  enters  one  of  the 
notches  in  the  edge  of  the  blank  and  thus  serves  as  a  locating  stop  to 
position  the  blank  in  alinement  with  the  grooves  in  the  punch  shown  at  C. 

The  next  operation  consists  in  placing  the  blank  in  the  hand  screw 
machine,  cutting  the  shallow  groove  around  the  outer  face,  as  at  F,  to  allow 
carbonization  of  the  blank  along  this  channel  only.  The  copper  surface 
protects  the  remainder  of  the  work  in  the  heating  process. 

The  next  operation  is  performed  in  the  press  with  the  punch  and  die 
at  G  and  H.  The  lower  die  has  at  /  a  round-ended  locating  stop  on  which 


Hr^Diam.  Filisterhead  Screw,  %"/ong 


•  2,]f.Diam.  Domls 


Top  View  of  Die 


casr  IRON 


.  §s  i  iu  i  i 

*>l  ^\ -ri  ' !    Ml^%-4#^5£3. TT 


fl^/rar  /v/c/ar 
(and  White  Filling) 

FIG.  428 

^:;:-;-H/7wff  Center  of  Shoe 
Fit  to  Die  Shoe 

FIGS.  428,  430.  —  Tools  for  indicator 

the  blank  is  nested  in  position  on  this  die  and  which  locates  the  outer 
serrations  correctly  in  relation  to  the  die  teeth  below.  This  lower  die 
also  carries  an  ejector  pin  at  the  center  for  forcing  the  blank  out  of  the  die 
ring  upon  the  upstroke  of  the  press.  The  action  of  the  upper  die  in  its 
descent  over  the  corner  pillars  is  to  force  the  ratchet-shaped  teeth  through 
the  side  of  the  groove  in  the  blank  at  one  stroke.  The  next  operation  is 
hardening  the  smooth  surfaces,  the  outside  serrations  around  the  blank, 
the  ratchet  teeth  outside  and  inside  wherever  the  bare  metal  is  exposed  by 
machining  after  copper-plating  the  piece.  That  is,  wherever  the  blank  is 
exposed  by  machining  after  coppering  the  piece,  it  hardens  to  prevent  wear 
of  the  tooth  edges. 


306 


PUNCHES  AND  DIES 


A  crank  is  used  for  adjusting  the  typewriter  carriage  in  relation  to  the 
type,  to  allow  for  one  or  more  thicknesses  of  paper,  according  to  the  char- 
acter of  the  work  being  done  on  the  typewriter.  In  the  movement  of 
this  crank,  it  passes  over  the  face  of  an  indicator  dial  at  the  front  of  the 
machine.  This  dial  is  graduated  in  the  manner  indicated  in  Fig.  428,  the 
numbers  running  from  0  to  16.  There  is  a  f-in.  hole  in  the  center  of  this 
plate,  which  passes  over  the  neck  of  the  adjusting  screw.  This  plate  is 
pierced  and  blanked  with  the  tools  shown  in  Figs.  429  and  430. 


FIG.  429.  —  Tools  for  indicator  blank 

As  will  be  seen  upon  examination  of  the  illustrations,  these  press  tools 
are  of  tandem  character;  that  is,  the  three  holes  are  pierced  in  the  stock 
before  the  blanking  is  done.  At  the  same  stroke  that  puts  the  three  holes 
in,  the  graduations  and  the  numerals  are  struck  into  the  face  of  the  stock. 
The  next  advance  of  the  strip  of  metal  feeds  the  work  against  stop  pins  at 
the  left-hand  side  of  the  die.  The  following  downstroke  of  the  press  and 
blanking  tools  cuts  the  work  out  to  the  outline  shown.  The  lower  face 
of  the  blanking  punch  will  be  seen  provided  with  a  conical-pointed  pilot 
pin  that  enters  the  f-in.  hole  already  pierced  in  the  work. 

The  small  piercing  punches  for  the  two  screw  holes  are  made  of  TVm- 
drill  rod  turned  down  to  the  required  size  for  the  screws.  The  stripper 
plate  is  countersunk  deeply  around  the  opening  for  these  small  punches  in 
order  that  the  neck  of  the  punches  may  pass  wall  down  into  the  plate  and 
give  suitable  support  to  the  ends  of  the  small  punches  themselves.  Owing 
to  this  liberal  opening  in  the  stripper,  the  punches  are  made  with  a  sweeping 


DIES  FOR  EMBOSSING,   MARKING,  RIVETING,  SWAGING       307 

fillet  instead  of  being  brought  to  anything  like  a  sharp  corner.  Thus  they 
are  much  more  substantial  in  operation  than  is  often  the  case  where  a  liberal 
fillet  of  this  kind  is  not  permissible. 

The  plan  view  at  the  upper  right-hand  corner  in  Fig.  430,  showing  the 
base  of  the  embossing  and  piercing  punch  as  well  as  the  blanking  punch, 
illustrates  clearly  the  method  of  attaching  both  punch  blocks  to  their 
cast-iron  carrying  block.  Three  screws  are  used  in  the  case  of  the  graduat- 
ing die,  along  with  a  pair  of  dowels,  while  four  screws  are  applied  to  the 
holding  of  the  blanking  punch  itself. 


FIG.  431.  —  An  embossed  piece 

AN  EMBOSSED  CRESCENT 

The  arc  shaped  piece  in  Pig.  431  is  manufactured  of  0.101-in.  brass 
with  the  press  tools  in  Fig.  432.  The  blanking  dies  at  the  left  have  no 
special  features  beyond  the  pillar  arrangement  for  guiding  the  punch  plate 
and  the  trigger  form  of  stop  actuated  by  the  adjustable  screw  in  the  punch 
holder.  The  embossing  dies  are  shown  at  the  center  of  the  group  in  the 
photograph. 

The  embossing  on  this  piece  of  work  consists  in  the  striking  up  of  the 
three  beveled  edged  bosses  AAA  in  the  body  of  the  crescent  and  the  off- 
setting of  the  two  ends  from  that  body  by  an  amount  indicated  by  the 
dimensioned  drawing,  Fig.  431. 

The  construction  of  punch  and  dies  is  simple  enough  to  require  little 


308 


PUNCHES  AND  DIES 


description,  as  the  principal  features  are  well  shown  by  the  photograph, 
Fig.  432.  The  bottom  of  the  die  seat,  which  is  bored  out  in  a  piece  of 
tool  steel,  is  lined  with  steel  ring  sections  to  form  the  die  thickness  at  the 


No.  289 
2  Eeq..035  S. S. Steel 


FIG.  432.  —  Blanking,  piercing  and  embossing  series  for  a  coin  register  part 

points  where  the  offsets  are  desired,  and  corresponding  sections  made  the 
reverse  of  the  die  members  are  fitted  into  the  punch  proper  as  shown.     The 

round  bosses  forced  up  from  the  surface  of  the 
metal  are  formed  by  bevel  head  studs  of  hard- 
ened tool  steel  seated  into  the  face  of  the  punch 
plate  and  operated  against  similar  depressions 

—r- ^r==~^~~~~T^' "        bored  and  countersunk  in  the  chamber  of  the 

I      /O- ^\\  ^e*    ^e  ^e  ^ase  *s  Provided  with  a  knockout 

in  the  form  of  small  pins  operated  by  the  handle 
at  the  front  which  enables  the  work  to  be 
ejected  with  convenience  after  it  is  struck  up. 
The  dies  at  the  right  in  the  photograph 
receive  the  embossed  blank  and  pierce  two 
small  holes  through  near  the  ends  as  indicated 
FIG.  433.  —  Embossed  disk      in  the  blueprint. 

TOOLS  FOR  A  RING 

The  ring  in  Fig.  433  is  embossed  or  formed  with  a  series  of  radial  V 
depressions  and  rises,  the  work  being  struck  up  between  the  dies  in  Fig. 
434,  at  the  left-hand  side.  The  other  dies  at  the  right  accomplish  the 


DIES  FOR  EMBOSSING,   MARKING,   RIVETING,   SWAGING       309 


previous  operations  of  piercing  and  blanking  the  ring  progressive-die 
fashion.  The  center  hole  being  pierced  at  this  time  provides  a  method  of 
locating  the  work  in  the  embossing  dies  by  slipping  it  over  the  pilot  in  the 
lower  die  center.  The  upper  and  lower  dies  are  alike  except  for  the  one 
having  a  pilot  and  the  other  a  bore  corresponding  in  diameter.  The  two 


FIG.  434.  —  Ring  embossing  tools 


FIG.  435.  —  Embossing  dies  for  a  disk 

dies  are  turned  and  milled  and  finished  and  hardened  and  then  secured  to 
the  die  base  and  upper  holder,  by  means  of  fillister  head  screws  and  dowels 
in  the  flange  around  the  die. 

EMBOSSING  AN  ALUMINUM  PLATE 

The  engraving,  Fig.  435,  illustrates  a  set  of  simple  dies  for  embossing 
radial  ribs  along  the  bottom  of  an  aluminum  disk  like  the  one  seen  to  the 
left  in  the  photograph.  The  feature  of  interest  here  is  in  relation  to  the 


310 


PUNCHES  AND   DIES 


manner  of  making  up  these  tools.  In  the  case  of  the  die  proper  with  con- 
cave channels  running  toward  the  center,  the  method  of  machining  was  to 
use  a  formed  end  mill  and  index  the  die  on  the  dividing  head  of  the  miller. 
The  punch  plate  or  upper  die  was  built  up  with  convex  faced  sections  of 
the  right  thickness  and  radius  which  were  fitted  into  radial  channels  and 
secured  there  as  integral  parts  of  the  die. 

A  LARGE  SET  OF  DIES 

The  dies  in  Fig.  436  are  one  of  a  number  of  similar  sets  used  for  or- 
namenting and  strengthening  the  edges  of  certain  sheet  metal  receptacles 
by  embossing  a  simple  design  around  the  surface  of  the  rings.  The  dies 


FIG.  436.  —  Large  embossing  dies 

for  this  work  are  cast  to  form  and  finished  up  by  filing,  scraping,  etc.,  to 
bring  the  embossing  portions  to  sufficiently  close  relationship  to  one  an- 
other to  answer  the  purpose  for  which  they  are  designed.  The  die  metal  is 
a  close  grained  iron  which  when  poured  gives  a  smooth  surface  without 
serious  pitting  or  roughness  of  any  kind. 

A  STAMPING  OR  MARKING  DIE 

In  Fig.  437  is  an  illustration  of  a  set  of  dies  for  stamping  the  numerals 
on  the  face  of  the  front  cover  of  a  calculating  machine  which  give  the  posi- 
tions for  the  setting  dials.  Fig.  438  shows  the  work  to  be  a  brass  plate 
0.040  in.  thick,  which  is  blanked  out  a  little  more  than  5  in.  square  and 


DIES  FOR  EMBOSSING,  MARKING,   RIVETING,   SWAGING      311 


then  stamped  under  the  tools  described.  In  the  blanking  operation  the 
nine  slots  are  punched  out  3  in.  long  by  ^  in.  wide,  leaving  a  width  of  stock 
about  T\  in.  for  the  stamped  numbers. 

The  punch  is  made  up  of  nine  rows  of  figures  from  0  to  9,  the  characters 
in  each  row  being  engraved  on  a  solid  block  so  that  there  are  nine  of  these 


FIG.  437.  —  Dies  for'stamping  numerals 

stamp  blocks  with  10  characters  each.  The  body  of  the  block  in  which 
they  are  fitted  is  planed  out  to  receive  them  as  a  snugly  assembled  unit, 
and  their  ends  are  locked  by  clamps,  set  screws  acting  against  the  ends 


1 5.06'- 

0.093  "Wide  >La  7ZQ" 


QZ75 "Apart,  Clearing  Slcts  Qj  " 

FIG.  438.  —  The  stamped  and  formed  plate 

and  the  sides  being  placed  in  the  block  to  set  the  whole  group  of  stamps  up 
tightly. 

The  rear  ends  of  the  stamps,  or  figures,  rest  upon  a  hardened  and  ground 
steel  plate  in  the  punch  block,  which  resists  the  pressure  of  the  90  charac- 
ters when  they  are  forced  into  the  work.  Similarly  the  base  of  the  die  is  of 
steel  hardened  and  ground  to  back  up  and  support  the  work  when  struck 
with  the  punch. 


312 


PUNCHES  AND   DIES 


It  has  been  estimated  that  if  this  combined  punch  with  its  90-figure 
stamps  were  to  be  operated  under  the  usual  power  press  or  in  a  manner 
similar  to  the  handling  of  a  coining  job,  a  pressure  somewhere  between 
150  and  175  tons  would  be  necessary  to  stamp  the  entire  set  of  characters 
properly  into  the  plate.  These  tools  are,  however,  not  used  in  such  a  press, 
but  under  a  drop  hammer  which  is  a  homemade  machine,  giving  satis- 
factory results  with  little  outlay  for  equipment. 

If  the  illustration  of  the  dies,  Fig.  437,  is  examined  carefully,  a  guide 
plate  for  the  work  will  be  noticed  at  the  left  side  and  at  the  right  two  small 
clamps  will  be  seen.  There  is  an  adjustable  stop  at  the  rear  of  the  die 


FIG.  439.  —  Blanking  dies  for  typewriter  type  bar 

base,  and  at  the  front  is  located  another  stop  which  confines  the  work 
edgewise  so  that  it  is  properly  nested  and  held  all  the  way  around. 

While  there  are  two  clamp  screws  to  turn  up  at  each  setting  of  a  fresh 
piece  of  work  on  the  die,  this  takes  but  a  moment,  and  the  entire  operation 
of  opening  the  die,  setting  the  work,  and  operating  the  drop  is  performed 
easily  and  rapidly. 

After  the  covers  have  been  numbered  along  their  slots  they  are  re- 
quired to  be  bent  up  to  the  general  form  indicated  in  the  end  view  in  Fig. 
438,  where  the  central  portion  with  the  slots  and  numbered  sections  is 
formed  to  an  arc  of  about  a  quarter  circle,  and  one  flat  portion  at  an 
angle  with  the  opposite  edge. 

The  brass  plate,  after  it  has  been  stamped  and  slotted,  is  annealed  and 


DIES  FOR  EMBOSSING,   MARKING,  RIVETING,   SWAGING       313 

f]hus  made  ready  for  the  forming  process.  This  is  carried  on  with  a  pair 
of  simple  dies  made  to  the  outline  required  and  differing  from  each  other 
only  in  that  one  is  male  and  the  other  female,  and  the  radii  of  the  two  are 
varied  to  allow  for  the  thickness  of  the  metal  plate. 

PREPARING  TYPE  BARS  FOR  RIVETING 

This  form  of  type  bar  is  made  of  flat  steel  stock  in  the  punch  press 
with  the  aid  of  the  dies  in  Fig.  439.  The  work  consists  in  blanking  the  bar, 
punching  out  the  center  to  lighten  it,  and  piercing  the  central  holes  for 
connecting  the  mechanism  by  which  the  type  bar  is  operated  when  as- 
sembled in  the  typewriter. 


FIG.  440.  —  Detail  of  type  bar 

A  detail  of  the  blank  is  presented  in  Fig.  440.  This  drawing  with  the 
several  blanks  seen  in  the  foreground  of  Fig.  439  shows  clearly  the  unusual 
form  of  this  type  bar. 

Referring  to  Fig.  440  it  will  be  seen  that  the  type  bar  blank  is  3.685  in. 
long  over  all,  has  a  height  of  0.90  in.  and  a  height  over  the  rear  lug  of 
1.050  in.  The  greater  portion  of  the  stock  in  the  middle  of  the  material  is 
punched  out  to  lighten  the  blank  and  this  is  done  at  the  same  operation 
as  the  blanking  and  piercing  of  the  small  rivet  hole. 

It  will  be  noted  in  Fig.  439  that  little  waste  is  made  in  blanking  these 
bars.  The  upper  and  lower  dies  are  made  in  two  sections,  the  dividing 
line  being  along  the  central  hole  in  the  blank.  The  dies  are  of  the  com- 
pound type;  the  lower  member  carries  the  outside  blanking  punch  and  the 
upper  die  carries  the  piercing  punches  for  cutting  out  the  interior  of  the 
blank.  The  top  die  is  fitted  with  a  shedder  that  forces  the  blank  back 
into  the  scrap  strip  on  the  upstroke  of  the  press.  When  the  stock  feeds 
forward  again  the  strip  carries  the  blank  with  it.  The  next  down  stroke 
of  the  press  causes  the  projecting  member  at  the  front  of  the  upper  die, 
Fig.  439,  to  strike  the  blank,  which  is  still  retained  by  the  scrap,  and 
knock  it  out  of  the  strip  into  a  box. 

This  projecting  " knock-out"  is  shown  more  clearly  in  Fig.  441,  where 
the  tools  are  set  up  in  the  punch  press.  The  knockout  is  simply  a  block  of 


314  PUNCHES  AND  DIES 

steel  made  in  the  form  of  the  blank.  As  the  strip  of  stock  with  the  inclosed 
blank  feeds  under  this,  it  merely  presses  down  sufficiently  to  press  one 
blank  after  another  from  the  strip  of  stock.  The  strip  is  carried  through 
the  machine,  where  it  is  broken  up  into  comparatively  short  strips  of  scrap. 
The  blanking  portion  of  the  lower  die  is  supported  by  springs  and  is 
normally  flush  with  the  face  of  the  die,  as  indicated  in  Fig.  439.  The 
centers  of  the  blank  punched  out  (see  Fig.  440),  when  punched  down 


FIG.  441.  —  Type  bar  tools  in  the  press 

through  the  blank,  fall  through  the  holes  in  the  lower  die  and  out  of  the 
press  at  once,  without  being  carried  along  by  the  stock.  The  arrangement 
of  these  supporting  springs  under  the  lower  die,  as  well  as  the  construction 
of  the  shedder  for  the  top  die,  is  of  conventional  type  and  needs  no  special 
description.  It  may  be  pointed  out,  however,  that  these  tools  are  of 
heavy  general  construction,  and  the  blocks  on  which  they  are  mounted  are 
equally  well  proportioned.  The  material  handled  is  0.028  in.  thick  and  is 
tempered  bandsaw  steel,  so  that  the  material  puts  considerable  work  on 
the  tools  for  the  blanking  of  the  type  bar.  It  will  be  seen  from  Fig.  441 
that  a  heavy  type  of  press  is  used  to  operate  the  tools. 

Following  the  blanking  operation,  the  type  bars  are  flattened  and  thus 
straightened  from  end  to  end.  They  are  then  ready  for  grinding  to  width 
and  to  length  and  to  bring  the  front  or  working  face  truly  perpendicular 
to  the  guiding  bases,  bottom,  and  top. 

In  the  blanking  of  these  tvpe  bars  about  0.010  in.  is  left  to  grind  off  — 
0.005  in.  on  each  edge.  Similarly,  about  the  same  amount  is  left  at  the 


DIES  FOR  EMBOSSING,   MARKING,   RIVETING,   SWAGING       315 

front  end  to  assure  this  coming  square  with  the  upper  and  lower  edges  of 
the  bar.  The  blanks  are  handled  on  the  grinders,  130  of  them  held  at  a 
time  in  a  single  fixture,  so  that  they  are  really  ground  exactly  as  a  solid 
block  of  the  same  area  would  be  gone  over  by  the  abrasive  wheel. 

The  fitting  of  the  type  to  the  end  of  the  type  bar  is  an  important  op- 
eration, involving  some  interesting  methods  and  fixtures. 

There  is,  however,  one  more  point  to  this  operation  which  it  may  be 
well  to  describe  in  connection  with  what  has  gone  before  in  reference  to 
making  these  type  bars  —  namely,  the  piercing  tools  for  the  three  holes 


FIG.  442.  —  Piercing  holes  in  end  of  type  bar 

at  the  front  end  of  the  type  bar,  to  receive  the  rivets  for  later  fixing  the 
type  in  place.  The  piercing  tools,  Figs.  442  and  443,  used  in  conjunction 
with  the  tools  for  making  the  corresponding  holes  in-  the  type  body  proper, 
assure  the  type  being  so  fixed  upon  the  end  of  the  type  bar  that  it  can 
never  be  displaced  or  loosened  in  any  manner. 

The  method  of  nesting  the  work  will  be  apparent,  as  it  is  here  shown 
with  the  lower,  or  bearing,  edge  pressed  against  the  stop  guide  at  the  back 
by  the  two  spring  punches  QQ,  which  apply  sufficient  pressure  to  hold  the 
blank  in  nest  A ,  and  against  the  top  surface  without  likelihood  of  springing. 


316 


PUNCHES  AND  DIES 


The  endwise  position  of  the  work  relative  to  the  dies  is  determined  accu- 
rately by  the  slide  R,  which  is  pressed  forward  against  the  action  of  the 
pressure  spring  by  the  taper  plunger  J  carried  by  the  punch  block.  In 
Fig.  442  this  punch  block  is  seen  descending,  and  the  taper  plunger  is  about 
halfway  down.  Just  before  the  piercing  plungers  have  reached  the  work, 
the  taper  plunger  brings  a  straight  portion  of  its  body  against  the  rear 
end  of  the  slide  R,  Fig.  443,  holding  this  in  position  and  consequently  hold- 
ing the  work  at  the  exact  point  for  piercing  the  three  holes  at  a  definite 
distance  from  the  front,  or  working,  end  of  the  type  bar.  This  position, 
being  the  work  of  the  combination  slide  R  and  the  plunger  J,  is  further 
aided  by  the  pressure  pad  H,  which  is  forced  down  on  the  work  and  holds 
it  steady  during  the  lift  of  the  punches. 


Pierced  Rivet 
Holes  to  Tj-pe  Back 


FIG.  444 

FIGS.  443-444.  —  Dies  for  piercing  rivet  holes 

The  arrangement  of  the  three  piercing  punches  is  shown  clearly  in  the 
elevation,  Fig.  443.  They  consist  of  drill  rods  turned  down  at  the  end  to 
form  a  light  punch  and  have  a  head  at  the  rear  end  to  retain  them  in  their 
guide  bushings.  The  latter  are  fitted  securely  in  the  punch  carrier  and  are 
long  enough  to  give  the  piercing  punches  proper  support  for  the  greater 
portion  of  their  length.  Immediately  behind  the  head  of  the  piercing 
punch  is  a  short  plug  about  If  in.  long,  of  J-in.  diameter,  and  behind  this  is 
the  head  of  the  screw.  It  is  therefore  an  easy  matter  to  adjust  the  punch 
to  strike  the  work  at  the  desired  instant,  and  the  three  punches  can  be  stag- 
gered for  giving  the  shearing  action  as  desired. 

The  method  of  setting  the  guide  bushings  will  be  apparent  upon  in- 
spection of  the  plan  view  and  the  accompanying  elevation,  showing  the 
two  members  of  the  press  tools,  Fig.  443,  so  that  little  further  explanation 


DIES  FOR  EMBOSSING,   MARKING,  RIVETING,   SWAGING       317 

will  be  necessary.     These  tools  are,  of  course,  guided  by  pillars,  so  that 
they  are  operated  similarly  to  subpress  tools. 

Referring  to  Fig.  442,  an  interesting  gaging  device  is  shown  at  the 
right  upon  the  stand,  this  being  the  test  gage,  not  only  for  the  accuracy 
of  the  type  bar  itself,  but  for  testing  the  placing  of  the  rivet  positions  rela- 
tively to  the  front  end  and  to  the  bottom  of  the  bar.  This  gage  has  a 
nest  at  the  top,  made  to  accurate  outlines  to  correspond  with  the  blank 
itself  and  with  location  holes  corresponding  to  the  rivet  holes  and  the 
larger  holes  pierced  near  the  center  of  the  type-bar  blank.  This  nest  is 
formed  on  the  top  of  a  pad  that  operates  against  spring  pressure.  The 
test  is  to  place  the  blank  upon  the  nest  pad  and  push  the  whole  thing  down 


FIG.  445.  —  Details  of  type  piercing  dies 

to  see  if  the  outer  edges  at  the  bottom  and  ends  will  just  slide  past  the 
corresponding  shearing  edges  of  the  test-gage  body.  This  corresponds 
closely  to  what  might  be  called  the  thumb-nail  test,  as  commonly  applied 
in  the  case  of  a  flush  pin  gage,  where  the  thumb  nail  is  passed  over  two 
edges  supposed  to  be  flush  and  where  a  fraction  of  a  thousandth  discrep- 
ancy is  easily  detected  if  there  is  any  lack  of  uniformity.  Such  is  the  case 
here.  If  the  end  of  the  type-bar  blank  or  if  the  lower  edge  should  project 
at  any  point  by  even  0.0001  in.,  this  would  interfere  with  the  punches 
descending  if  pressed  lightly  with  the  finger. 

The  piercing  tools  for  the  type  take  care  of  all  of  the  type  for  the  ma- 
chines and  must  therefore  be  adaptable  to  conform  to  the  various  angles 
to  which  the  bodies  of  the  type  are  milled  in  relation  to  the  printing  faces 


318 


PUNCHES  AND  DIES 


of  the  characters.  In  Fig.  444  a  sketch  is  reproduced  showing  the  position 
of  the  small  rivet  holes  in  both  type  bar  and  type,  and  in  Fig.  445  is  a 
detailed  drawing  of  the  dies  for  piercing  the  holes  in  the  type.  The  ad- 
justable locator  DD  takes  care  of  all  angles  of  type  and  the  work  is  held 
securely  in  its  nest  by  the  clamp  B.  It  is  not  essential  to  enter  into  a 
detailed  description  of  this  die  but  its  features  are  called  attention  to,  as 
worth  study  by  those  designing  adjustable  tools  for  various  classes  of  work. 


FIG.  446.  —  Piercing  for  type  rivets 

The  dies  are  shown  in  operation  in  Fig.  446. 

The  important  part  of  many  riveting  undertakings  is  not  the  actual 
riveting  process  but  the  preparation  in  the  piercing  of  the  holes  for  the 
rivets.  The  riveting  tools  are  as  a  rule  very  simple  devices,  many  ex- 
amples of  which  are  included  in  the  half  tone,  Fig.  27 ,  in  Chapter  I.  With 
holes  properly  pierced  so  that  they  aline  and  with  suitably  formed  rivets 
the  riveting  dies  present  no  difficulties  in  making  or  using.  For  various 
examples  of  different  shapes  of  riveting  tools  the  reader  is  referred  back 
to  the  above  illustration. 


DIES  FOR  EMBOSSING,   MARKING,   RIVETING,   SWAGING       319 


A  SET  OF  RIVETING  OR  STAKING  TOOLS 

The  three  steel  parts  in  Figs.  447,  448,  and  449  are  members  of  a  coin 
wheel  that  are  made  in  the  dies,  Figs.  450,  451,  and  452,  and  assembled 
and  riveted  or  staked  by  the  tools  in  Fig.  453. 

No.l22-2Req. 


No.l37-2Req. 
.093  "x  %"x 

H.S.Steel 


.'093 
ENLARGED  SCALE 

FIG.  447.  —  Spacing  piece  for  a  coin  wheel 


FIG.  448.  —  Coin  wheel  member 


The  blanking  dies  in  Figs.  450  and  451  are  of  simple  form  and  the 
blanking1  and  piercing  tools  for  the  disk,  Fig.  449,  are  of  the  progressive 


No.133-2  Req. 
.050'xsH'x  3H" 
•^/       H.S.Steel 
^Coiii  Wheel  Disk 

\ 


FIG.  449.  —  Coin  wheel  disk 

type  as  shown  by  Fig.  452.  The  long  blank,  Fig.  451,  is  bent  up  to  the 
outline,  Fig.  448,  by  the  hand  forming  tools  at  the  right  in  Fig.  451.  The 
tools  by  which  the  parts  are  fixed  together  in  Fig.  453  are  made  up  of  a 
base  A  with  an  open  nest  for  the  dial  which  rests  therein  after  the  riveting 


320 


PUNCHES  AND  DIES 


FIG.  450.  —  Blanking  dies  for  piece  Fig.  447 


FIG.  451.  —  Blanking  and  bending  tools  for  work  in  Fig.  448 


FIG.  452.  —  Blanking  and  piercing  dies  for  coin  wheel  disk  Fig.  449 


DIES  FOR  EMBOSSING,   MARKING,   RIVETING,   SWAGING       321 


PIG.  453.  —  Riveting  dies  for  coin  wheel 


FIGS.  454-455.  —  Swaging  dies 

lugs  on  the  other  members  have  been  placed  into  the  pierced  slots  in  the 
disks.  The  partially  assembled  wheels  are  shown  in  front  of  the  tools  and 
the  arrangement  of  the  riveting  punches  in  the  holders  will  be  understood 
from  the  engraving.  These  punches  are  made  with  V-shaped  points  to 
strike  the  end  of  the  lugs  and  spread  them  sufficiently  to  hold  the  parts 
together.  The  punch  holder  carries  a  pressure  pad  B  to  hold  the  work 
while  the  operation  is  performed. 


322 


PUNCHES  AND   DIES 


SWAGING  DIES  FOR  AN  Am  RIFLE  PART 

The  die  shown  in  Fig.  454  was  made  for  producing  the  shot  seat  A, 
Fig.  455,  for  an  air  rifle.  Brass  tubing  is  used  |  in.  outside,  a  little  under 
T\  bore  and  the  washer  hole  is  made  slightly  over  J  in.  With  a  circular 
saw  the  tubing  is  cut  f  £  in.  long  and  then  the  pieces  are  tumbled.  As 
can  be  seen  from  Fig.  454,  the  die  upsets  the  wall  of  the  tube,  increases  and 
tapers  the  outside  diameter,  and  forms  a  choke  bore  about  ££  in.,  leaving 


Finishing  Die  Bushing 
Double  Size 

FIG.  456.  —  A  forming  die  for  a  brass  tube 

the  outer  end  tapered  to  hold  the  shot;  besides  throwing  up  a  bead  at  B 
and  turning  over  the  lower  end,  thus  securely  seating  the  tube  in  the 
washer. 

The  construction  of  the  die  is  shown  in  Fig.  455.  The  springs  hold  up 
the  die  and  also  return  the  knockout.  In  operation  the  washer  and  the 
tube  are  assembled  and  placed  in  the  die,  the  tube  resting  on  the  knockout 
pin,  which  also  acts  as  a  mandrel  to  form  the  funnel-shaped  mouth,  and 
the  washer  resting  on  the  die.  The  f-in.  motion  of  the  die  keeps  the  washer 
in  the  right  position  on  the  tube  while  the  latter  is  being  upset.  The  die  is 
countersunk  at  the  top  to  form  the  bead  over  the  washer. 


DIES  FOR  EMBOSSING,  MARKING,  RIVETING,  SWAGING      323 

On  the  downstroke  the  dog  F  swings  in  and  passes  E  and  D,  but  on  the 
upstroke  it  engages  the  hook  D  and  pulls  out  the  finished  piece;  as  F  is 
wider  than  D,  E  pushes  it  out  of  engagement  with  D.  The  die  being 
tapered,  the  only  resistance  that  the  knockout  has  to  overcome  is  right  at 
the  beginning  of  the  pull,  when  the  dog  is  in  full  engagement  with  the 
hook.  At  the  point  of  release  the  only  stress  is  from  the  pair  of  light 
springs,  so  that  the  wear  on  the  points  is  nominal. 

SWAGING  A  SMALL  BUSHING 

The  dies  in  Fig.  456  are  for  swaging  or  forming  the  ends  of  the  small 
tube  shown  in  Fig.  457,  where  A  is  the  blank  and  B  the  swaged  product. 
The  drawing,  Fig.  456,  shows  two  dies  for  swaging  down  the  tube  ends. 


BLANK 


32       Brasstube 

FIG.  457.  —  Tube  swaged  at  ends 

The  first  gives  a  straight  taper,  the  other  forms  a  curved  end.  The  work 
is  placed  in  the  swiveling  holder  C  swung  to  the  right  for  the  swaging  of  the 
taper  end,  moved  to  the  center  for  the  next  blow  which  swages  the  curved 
outline,  and  then  swung  to  the  left  for  the  knockout  punch  to  push  the 
work  down  out  of  the  dies.  The  swinging  holder  C  has  a  locating  tongue 
to  fit  the  index  slots  DDD  at  the  front  of  the  die  base.  In  addition,  aline*- 
ment  with  the  upper  dies  is  assured  by  the  cone  pointed  pin  E  which 
enters  a  guide  hole  in  the  bracket  F  attached  to  the  rear  of  the  upper  head. 
There  are  three  of  these  guide  bushings,  as  shown  at  GGG  in  the  plan  view. 
They  are,  of  course,  located  upon  an  aro  struck  from  the  same  center  as  the 
pivot  which  carries  the  swinging  work  holder  C. 


CHAPTER  XIII 
INDEXING  AND   TRANSFER  DIES 

The  processes  of  piercing,  notching,  graduating,  drawing,  etc.,  are 
often  carried  on  in  the  press  by  the  aid  of  some  form  of  indexing  die  or, 
again,  by  a  transfer  tool  which  shifts  the  work  from  one  position  to  the 
next  with  marked  advantage  in  one  way  or  another  over  the  usual  hand 
method  of  placing  the  blank  as  required. 

A  few  typical  forms  of  such  devices  as  incorporated  in  the  dies  them- 
selves are  illustrated  briefly  in  the  present  section.  The  first  of  these  is 
shown  by  Fig.  458  which  represents  a  notching  device  for  disks  for  elec- 
trical work.  This  is  one  of  the  commonest  forms  of  indexing  die,  as  num- 


FIG.  458.  —  Indexing  die  for  notching  disks 

bers  of  similar  tools  or  dies  operated  on  the  same  general  principle  are  used 
for  this  class  of  work. 

This  particular  set  of  dies  pierces  three  slots  at  each  stroke,  the  punch 
being  a  triple  device  as  indicated.  It  might,  however,  be  a  single  punch 
or  the  holder  might  carry  more  than  two  or  three  according  to  conditions. 
So  far  as  the  punch  is  concerned,  it  may  be  stated  that  it  carries  a  stripper 
which  is  backed  up  by  a  rubber  buffer  and  the  punch  sections  are  let  into 
a  steel  holder  which  is  made  with  a  round  shank  to  fit  the  slide. 

The  die  is  located  at  the  front  side  of  the  indexing  dial  and  the  latter 
is  in  the  form  of  a  ring  with  gage  pins  which  enter  notches  in  the  edge  of 

324 


INDEXING  AND  TRANSFER   DIES 


325 


IP 


FIG.  459.  —  An  indexing  perforating  die 


FIG.  460.  —  Indexing  die  with  work  in  place 


326 


PUNCHES  AND   DIES 


the  work  to  locate  the  disk  and  cause  it  to  rotate  when  the  index  ring  is 
advanced  by  the  ratchet  teeth  and  pawl  at  the  side.  There  are  two  pawls 
at  the  left  side,  one  for  feeding  the  ring  ahead,  the  other  for  locking  it 
against  backward  movement  when  the  feed  pawl  is  being  swung  to  the 
rear,  preparatory  to  giving  the  indexing  ring  its  next  forward  movement. 

AN  INDEXING  PERFORATING  DIE 

The  indexing  tools  in  Fig.  459  are  for  perforating  the  aluminum  ar- 
ticle at  the  center,  through  the  side  walls,  with  groups  of  small  openings, 
numbering  48  holes  in  a  group  and  16  groups  or  768  holes  in  all.  The 


FIG.  461.  —  Mechanism  at  rear  of  indexing  die 

punches  are  placed,  48  of  them,  in  a  punch  plate  fitted  to  the  holder  at  the 
right  and  a  close  fitting  stripper  is  mounted  on  the  holder  in  the  manner 
indicated.  The  work  is  shown  in  place  on  the  index  plug  in  Fig.  460  and 
in  Fig.  461  the  method  of  arranging  the  punch  holder  to  actuate  the  index 
mechanism  will  be  seen. 

The  bottom  of  the  work  has  been  perforated  in  an  earlier  operation 
and  here  there  are  three  pins  in  the  end  of  the  index  plug  that  enter  three 
holes  pierced  in  the  work  and  act  as  drivers  for  the  piece.  The  lever  at 


INDEXING  AND  TRANSFER  DIES 


327 


the  front  with  the  large  disk  attached  is  swung  around  and  latched  as  in 
Fig.  460  to  hold  the  work  on  the  fixture.  The  die  is  in  the  form  of  a  horning 
die  with  diameter  to  fill  the  cup  and  the  outer  shell  fixed  to  hold  the  die 
which  is  fitted  into  it  along  the  top  center  line.  The  rotary  part  is  an  in- 
ternal plug  or  arbor  that  carries  the  three  driving  pins  as  described  before. 
When  the  ratchet  wheel  is  actuated  by  the  pawl  at  the  rear,  Fig.  461, 
the  arbor  with  the  work  is  rotated  ahead  one  notch  and  the  work  thus 
brought  into  place  for  the  piercing  of  a  fresh  group  of  holes.  The  pawl  is 
carried  upon  a  slide  at  the  back  which  is  actuated  by  the  up  and  down 
movement  of  the  press.  A  stop  pin  in  the  face  of  the  ratchet  wheel  acts 
to  release  the  feed  pawl  upon  the  completion  of  one  revolution  of  the  work* 

NOTCHING  A  COMB 

The  detail  in  Fig.  462  represents  a  typewriter  comb  which  is  notched 
in  the  indexing  die  shown  by  Figs.  463  to  466.  The  work  is  made  from 
phosphor  bronze  0.032  in.  thick  and  is  bent  up  to  a  circular  channel  with 


FIG.  462.  —  Typewriter  comb 

an  outer  radius  of  about  3|  in.  There  are  28  notches  cut  in  the  flanges 
around  this  arc  shaped  piece  and  these  are  spaced  in  accordance  with  the 
angular  measurements  given  on  the  drawing. 

The  indexing  fixture  is  shown  clearly  in  the  photographic  views,  the 
first  of  these,  Fig.  463,  illustrating  the  working  face  of  the  holding  fixture 
in  position  on  its  spindle  and  the  machine  ready  for  operation.  The  ap- 
pearance of  the  comb  before  and  after  this  punching  operation  is  well 
brought  out  in  Fig.  463,  while  the  principal  dimensions  are  included  in 
Fig.  462.  The  details  of  construction  of  the  fixture  are  show.n  in  Fig.  466. 
The  general  method  of  operation  will  be  obvious  upon  examination  of  the 
various  illustrations. 

Referring  to  Fig.  464,  which  shows  the  work-holding  plate  removed, 
it  will  be  seen  that  the  inner  face  of  this  plate  is  provided  with  a  seat  in 
the  form  of  an  arc,  into  which  the  work  is  slipped  and  in  which  it  is  lo- 


328 


PUNCHES  AND  DIES 


I 


••3 
to 


INDEXING  AND  TRANSFER  DIES 


329 


cated  endwise  by  suitable  stop  pins  that  hold  it  in  place.  When  the  work 
plate,  A,  Fig.  463,  is  put  back  in  place  on  the  spindle,  it  is  held  against 
longitudinal  movement  by  the  open  washer  B.  This  slides  into  a  slot  in  the 
circumferential  groove  near  the  end  of  the  spindle  and  the  projecting 


FIG.  465.  —  Rear  of  notching  die 

flanges  of  the  work,  which  are  to  be  notched,  rest  upon  the  curved  surfaces 
at  CD.  These  are  more  clearly  seen  in  Fig.  3  which  shows  the  work  holding 
plate  removed. 

The  punch  E  is  a  cylindrical  body  with  two  cutting  teeth  inserted  at 
proper  distance,  one  above  the  other,  to  operate  upon  the  two  flanges 


330 


PUNCHES  AND  DIES 


simultaneously.  This  punch  is  illustrated  in  Fig.  464.  At  the  left  of 
the  punch  will  be  seen  the  mechanism  to  operate  the  pawl  by  which  the 
ratchet  wheel  at  the  rear  of  the  fixture  is  moved  upon  the  upstroke  of  the 
punch.  This  advances  the  work  one  space  farther  ahead  for  the  cutting 


of  the  next  pair  of  notches,  on  the  next  downstroke  of  the  press.  The  ar- 
rangement of  this  feed  mechanism  will  be  more  clearly  seen  in  the  rear 
view,  Fig.  465.  It  will  be  noticed  from  this  and  from  the  details  in  Fig. 
466  that  the  ratchet  wheel  is  provided  with  two  sets  of  teeth  on  opposite 


INDEXING  AND  TRANSFER  DIES  331 

edges.  The  fixture  answers  for  both  upper  and  lower  combs  by  changing 
the  ratchet  wheel. 

The  details  of  the  punches  also  are  shown  in  this  drawing  along  with  the 
guide  and  supporting  blocks  for  the  curved  edge  of  the  work.  The  details 
show  also  the  form  of  the  spindle  for  mounting  the  work  and  operating 
fixtures,  as  well  as  the  various  smaller  parts  that  enter  into  the  construction 
of  this  device. 

It  should  be  noted  that  the  work  holding  fixture,  which  is  in  the  form 
of  a  quadrant,  is  made  with  a  long  hub  to  pass  over  the  spindle.  Although 
this  is  easily  slipped  into  place,  the  bearing  is  sufficiently  long  to  give  it 
a  firm  position  upon  its  support.  This  makes  the  notching  process  free 
from  chatter  and  during  the  indexing  the  work  is  held  steady  for  the  punch- 
ing stroke. 

The  punch  holder  is  novel  in  construction  in  that  it  is  provided  with 
cross  slots  to  receive  the  flange  on  the  head  of  the  punch  and  allow  the 


FIG.  467.  —  Dies  for  graduating  a  straight  bar 

punch  to  be  adjusted  as  required.  Similar  means  are  used  for  mounting 
the  plunger  that  operates  the  indexing  devices.  This  device  is  operated 
at  the  usual  rate  of  the  punching  press,  and  it 'takes  less  than  a  minute's 
time  to  produce  the  complete  series  of  28  pair  of  notches. 

Referring  now  to  the  punch  E,  Fig.  463,  this  will  be  seen  to  be  of  novel 
construction.  It  has  a  body  which  is  about  f  in.  in  diameter  and  which 
slides  in  a  guide  of  the  same  size.  The  punch  body  is  fitted  with  two  cut- 
ting blades,  each  about  f  in.  long,  and  spaced  longitudinally  2  in.  apart 
so  that  they  strike  the  outer  and  inner  flanges  of  the  work  simultaneously. 

These  cutting  blades  are  also  adapted  to  form  the  angular  portion  of 
the  opening  at  the  top  of  the  notch,  which  is  formed  to  90  degrees  so  that 
the  cutting  portions  of  the  punch  are  similarly  made  at  this  angle.  As 
indicated,  the  punch  body  is  provided  with  a  Woodruff  key  to  prevent  it 
from  twisting  in  operation.  The  sleeve  of  the  flanged  head  for  securing 


332  PUNCHES  AND   DIES 

the  punch  in  the  punch  holder  is  made  to  fit  over  the  neck  on  the  punch 
and  is  connected  thereto  by  a  screw,  so  that  it  cannot  be  mislaid. 

The  tools  in  Fig.  467  are  for  indexing  a  straight  bar  while  numerals  and 
graduations  are  stamped  upon  its  surface.  The  punch  operates  in  the 
usual  fashion  over  the  die  and  the  work  which  is  attached  to  the  sliding 
carrier  on  the  ratchet  feed  bar  extending  from  the  face  of  the  die  shoe,  is 
fed  forward  a  definite  distance  each  stroke  so  that  it  assumes  the  correct 
position  over  the  die  for  each  graduation  or  character  stamped  upon  its 
surface. 

TRANSFER  DEVICES 

There  are  various  devices  on  dies  and  arrangements  for  removing 
the  work  from  one  section  to  another,  to  obviate  the  necessity  for  the  op- 
erator picking  the  piece  up  with  his  fingers  and  replacing  it  in  some  other 


FIG.  468.  —  Transfer  device  for  compound  die 

part  of  the  die.  An  illustration  of  a  set  of  dies  arranged  in  this  manner  is 
shown  in  Fig.  468  which  represents  the  method  of  blanking,  drawing,  and 
piercing  a  shell  in  a  compound  die  and  then  transferring  it  automatically 
to  a  swaging  die  for  reshaping  the  walls  of  the  piece. 

The  work  is  shown  in  'Fig.  469,  and  the  construction  of  the  tools  in 
Fig.  470.  From  the  latter  view  it  will  be  understood  that  the  blanking, 
drawing,  and  piercing  are  accomplished  at  one  stroke  in  the  dies  A  and  B, 
which  are  of  the  compound  type  and  so  clearly  shown  as  to  be  understood 
without  definite  reference  to  each  feature.  The  shell  emerges  from  these 
dies  with  straight  walls  and  is  transferred  automatically  to  the  die  C,  in 
front,  where  it  is  formed  to  a  taper  as  indicated  in  Fig.  469.  The  operation 
of  the  device  is  as  follows: 

When  the  punch  head  and  the  drawing  die  B  rise,  carrying  the  shell  up 
with  the  die,  the  transfer  arm  D  is  swung  by  cam  slot  E  into  line  with  the  die 
and  the  positive  knock  out  above  forces  the  work  down  into  the  split 
opening  in  the  end  of  the  arm  at  F.  On  the  down  stroke  this  arm  is  swung 


INDEXING  AND  TRANSFER  DIES 


333 


forward  by  the  cam  movement  and  alined  with  the  swaging  die  C  at  the 
front  of  the  shoe  so  that  the  punch  G  can  force  the  work  down  into  the 
tapering  die  C.  The  knock  out  in  this  auxiliary  die  is  at  H.  It  is  depressed 


CJ  Stripper  Pins  in  Die 


Section  Through  A  B 
'ElG.4  70     T..H  E  LBAHSEE.B.  D.I  ES 

.125" 
)27'' 


A    These.Pinstobe 

-tnl'        ...       \    ,,,,,LocatedM-    ' 

ijilK'  ]    i^n=y..^  Shown  above 


FIG, 469     THE;  WORK 
FIGS.  469-470.  —  Transfer  dies  for  a  cup 

by  the  forcing  down  of  the  shell  into  the  die  and  when  the  punch  head 
rises  it  is  carried  upward  by  the  action  of  the  bolts  II  and  the  cross  bar  J 
under  the  knock  out  screw  K.  This  clears  the  swaging  die  C  for  the 
reception  of  the  next  shell  upon  the  next  down  stroke  of  the  punch. 


CHAPTER  XIV 


THE   SUB   PRESS   AND   ITS   DIES 

The  sub  press  which  has  been  referred  to  briefly  in  the  opening  chapter 
of  this  volume  is  used  advantageously  in  many  lines  of  work,  particularly 
where  parts  to  be  produced  in  the  power  or  foot  press  are  quite  small,  of 
thin  stock,  intricate  in  outline  or  of  very  close  degree  of  accuracy.  Owing 
partly  to  the  fact  that  their  range  of  sizes,  as  generally  made,  is  somewhat 

limited,  and  also  to  the  first  cost  as 
compared  with  the  ordinary  types  of 
press  tools,  they  are  not  so  generally 
used  as  requirements  would  seem  to 
justify  in  the  average  line  of  close  man- 
ufacture; although  on  such  work  as 
clock  and  watch  parts,  meter  parts,  and 
numerous  other  lines  of  press  work 
they  are  employed  very  extensively. 

There  are  two  general  types  of 
sub  presses,  the  cylindrical  and  the 
pillar,  each  incorporating  the  princi- 
ple, however,  of  a  plunger  sliding  in 
a  bearing  which  is  attached  to  the 
casting  that  forms  the  base.  The 
cylindrical  type  is  illustrated  by  Fig. 
471,  the  pillar  type  by  Fig.  472. 
•The  latter  of  course  is  of  the  general 
design  that  has  been  so  commonly 
adopted  by  die  makers  who  have  re- 
quired a  more  accurate  type  of  press 
tool  than  the  plain  open  punch  and  die,  and  who  have  constructed  tools 
of  the  general  pattern  of  Fig.  472  for  a  widely  diversified  class  of  operations, 
not  only  on  small  parts  but  for  large  blanks  as  well;  for  this  class  of  die 
has  made  it  possible  to  secure  a  refined  product,  and  even  where  no  special 
degree  of  accuracy  is  required  it  has  enabled  press  tools  to  stand  up  to 
their  work  for  a  greater  period  of  time,  and  it  has  facilitated  the  operation 
of  setting  up  the  work  in  the  press  and  simplified  the  problem  of  tool 
upkeep. 

334 


471.  —  Overhang  type  of  sub  press 


THE  SUB  PRESS  AND  ITS  DIES 


335 


With  the  pillar  type  referred  to,  the  guide  pins  may  be  either  on  the 
center  line  or  at  the  rear  of  the  die  base;  or  the  two. pillars  may  be  placed 
at  diagonally  opposite  corners,  or  again  four  pillars  may  be  employed, 
one  at  each  of  the  four  corners  of  the  die.  The  location  and  number  of 
pillars  employed  depends  upon  the  size  and  shape  of  the  die  shoe  or  base. 
There  is  practically  no  limit  to  the  size  of  the  work  that  may  be  handled  in 
such  dies  except  the  limiting  capacity  of  the  press  itself.  The  various 
forms  of  construction  differing  somewhat  in  details  and  materially  in 
dimensions  have  been  illustrated  in  full  in  preceding  chapters. 

As  a  rule  the  pillar  type  of  sub  press  has  no  provision  for  compensating 
for  wear;  but  where  an  outfit  of  this  character  is  to  be  used  more  or  less 
continuously  the  pillars  may  be  of 
hardened  and  ground  steel,  and  the 
bearings  may  be  bushed  with  the 
same  material.  The  head  or  punch 
holder  may  be  provided  with  a  shank 
to  fit  directly  in  the  slide  of  the  press, 
or  the  shank  may  be  discarded  en- 
tirely and  the  punch  holder  secured  to 
the  lower  face  of  the  press  slide  by 
bolts  passing  through  drilled  holes  at 
the  ends  of  the  holder  and  tapped  into 
the  press  slide.  Or  again,  some  form 
of  adaptor  may  be  employed  for  con- 
necting punch  holder  and  press  slide. 
These  details  have  been  covered  in 
connection  with  various  illustrations 
of  dies  presented  in  other  chapters. 

We  have  come  ordinarily  to  call 

,  T      t{    .„         ,.     ,,  ,,    .„  FIG.  472.  —  Pillar  sub  press 

such  tools     pillar  dies      or     pillar 

type  sub  presses"  and  to  apply  the  term  "sub  press"  to  the  cylindrical  or 
barrel  form  of  die  in  Fig.  471.  This  sub  press  is  made  in  two  forms,  the 
overhang  pattern  of  Fig.  471  and  the  arch  form  which,  as  its  name  indicates, 
is  built  with  an  open  arch  frame  which  allows  the  stock  to  be  passed  directly 
through  from  side  to  side.  This  form  of  press  is  generally  used  for  blanking 
dies,  either  simple,  tandem  (or  progressive)  or  compound,  as  these  dies 
usually  work  from  the  strip  of  metal.  The  overhang  type  is  preferred  for 
second  operations  where  the  blank  must  be  placed  individually  in  the  dies, 
as  for  such  operations  as  piercing,  trimming,  shaving,  forming,  and  so  on. 
While,  as  already  pointed  out,  cylindrical  sub  presses  as  manufactured 
are  necessarily  limited  in  their  capacities,  it  will  be  of  interest  to  note  that 
they  are  regularly  made  with  plungers  that  range  in  diameter  from  lj\  in. 
to  6  in. 


336  PUNCHES  AND  DIES 

From  the  .drawing  it  will  be  seen  that  the  sub  press  has  a  cylindrical 
plunger  which  slides  up  and  down  in  a  babbitted  sleeve  or  bearing  held 
in  the  housing  or  barrel  by  a  cap  nut  at  the  top.  The  babbitt  sleeve  is 
tapered  externally  and  fits  a  similarly  tapered  seat  in  the  barrel,  so  that 
it  admits  of  adjustment  by  means  of  the  nut  to  retain  a  fit  for  the  plunger 
without  affecting  the  original  alinement. 

The  base  is  finished  with  a  shoulder  or  hub  that  is  machined  to  fit  the 
bored  opening  in  the  lower  end  of  the  barrel.  As  indicated  in  the  drawing 
the  upper  end  of  the  plunger  terminates  in  a  button  which  is  machined  to 
fit  into  a  member  known  as  a  hook  which  is  secured  to  the  press  slide. 

Sub  presses  of  this  kind,  when  supplied  without  the  dies  do  not  have 
the  base  and  barrel  fitted  to  each  other,  for  it  is  necessary  that  the  base 
recess  for  receiving  the  punch  or  die,  as  the  case  may  be,  should  be  bored 
at  the  same  setting  as  the  outside  of  the  shoulder  or  hub  is  turned  to  assure 
their  being  concentric  with  each  other.  It  is  customary  for  die  makers  to 
bore  the  opening  in  the  lower  portion  of  the  barrel  to  assure  its  coming 
true  with  the  plunger.  When  these  members  are  once  fitted  together, 
they  are  of  course  fitted  with  dowel  pins  so  that  they  may  afterward  be 
taken  apart  at  any  time  and  remounted  without  disturbing  the  aline^ 
ment.  < 

It  is  obvious  from  the  foregoing  that  the  cylindrical  type  of  sub  press 
has  the  marked  advantage  that  its  recesses  for  the  die,  punch  and  other 
members,  can  be  bored  true  with  one  another  more  readily  than  in  the 
case  of  other  designs.  It  is  true,  however,  that  the  usual  design  of  press 
as  used  for  the  ordinary  open  die  has  insufficient  height  to  admit  the  cylin- 
drical sub  press  of  standard  dimensions,  although  builders  now  make  lines 
of  presses  of  suitable  range  for  this  form  of  sub  press.  'Where  such  ma- 
chines are  not  available,  the  pillar  sub  press  is  used. 

THE  DIES  OF  THE  SUB  PRESS 

Tjrpical  blanks  produced  by  means  of  the  sub  press,  and  work  for  which 
this  type  of  press  is  especially  adapted,  are  illustrated  by  Figs.  473  and  474, 
the  first  of  these  representing  a  group  of  parts  pierced  and  blanked  by 
tandem  or  progressive  dies,  while  the  second  engraving  shows  a  variety  of 
parts  as  manufactured  in  compound  dies. 

There  are  cases  where  plain  blanks  without  holes  or  openings  of  any 
kind  are  preferably  made  in  sub  press  dies,  because  of  the  positive  alinement 
that  enables  the  closely  fitting  punches  and  dies  necessary  for  very  thin 
work  to  be  operated  without  shearing  and  with  accurate  results  on  the 
work. 

The  advantages  of  progressive  dies  and  the  additional  advantages  of 
compound  tools  have  been  discussed  fully  in  other  chapters  and  need 


THE  SUB  PRESS  AND  ITS  DIES 


337 


not  be  entered  into  here.  It  may  be  said,  however,  that  these  advantages 
are  quite  as  marked  in  the  case  of  the  sub  press  tools.  For  if  plain  blanking 
or  if  tandem  dies  tend  to  produce  blanks  that  are  slightly  distorted  and 
which  for  the  most  accurate  work  have  to  be  flattened  in  another  operation, 


FIG.  473.  —  Tandem  die  work  in  the  sub  press 

the  compound  die  in  the  sub  press  will  correct  this  trouble.  And  just  as 
the  progressive  die  will  facilitate  the  production  of  blanks  requiring  piercing, 
so  will  the  compound  die  perform  the  two  operations  as  one,  with  entire 
accuracy  between  the  contour  and  the  position  of  the  openings  pierced,  for 


FIG.  474.  —  Compound  die  work  in  the  sub  press 

there  is  no  shifting  of  the  work  between  the  operations  of  piercing  and 
blanking.  Moreover,  as  regards  compound  dies,  they  will  retain  their  size 
under  numerous  sharpenings  much  longer  than  other  types  of  dies  because 
of  the  reduced  clearance  angle  made  feasible  by  the  fact  that  the  work  does 
not  have  to  pass  clear  through,  but  is  instead  ejected  by  a  knock  out. 

In  Fig.  475  an  arch  type  of  sub  press  is  illustrated  with  compound  dies 
for  blanking  and  piercing  a  wheel  like  Fig.  476.  The  blanking  die  is  shown 
at  A,  the  blanking  punch  at  B.  The  piercing  punch  is  located  at  C  and 
the  piercing  die  opening  is  formed  at  D  in  the  center  of  the  blanking  punch 
B.  The  piercing  punch  is  provided  with  a  taper  shank  which  fits  a  taper 
hole  in  the  holder  E  and  it  is  further  secured  by  a  small  screw  tapped  in 
from  the  top. 


338 


PUNCHES  AND   DIES 


FIGS,  475-476.  —  Arch  type  of  sub  press 


THE  SUB  PRESS  AND  ITS  DIES 


339 


The  punch  holder  E  is  fastened  to  the  bottom  of  the  plunger  G  by  fil- 
lister head  screws  and  it  has  a  taper  hub  fitting  deeply  into  a  taper  seat  in 
the  plunger  end.  This  holder  serves  as  a  mount  for  the  blanking  die  A 
which  is  located  over  a  taper  shoulder  as  shown  and  held  by  the  same  screws 
that  pass  through  the  holder  E  into  the  plunger.  The  holder  E  is  drilled 
to  allow  the  pins  H  to  pass  through  into  contact  with  the  knock  out  I 
at  the  bottom  of  the  spring  chamber  in  the  plunger.  Adjustment  of  the 
spring  pressure  is  made  by  means  of  the  headless  screw  carried  by  the 
button  at  the  top  of  the  plunger.  The  pins  H  act  against  knock  out  disk 
J  which  ejects  the  blank  from  die  A  and  forces  it  back  into  the  scrap  stock 
which  carries  it  out  of  the  press. 


FIG.  477.  —  Sub  press  with  all  details  of  compound  clock  wheel  die 

The  stock  is  stripped  from  the  blanking  punch  B  by  the  spring  stripper 
K;  this  is  controlled  by  coiled  springs  on  fillister  head  screws  L  which 
travel  in  counterbored  holes  in  the  press  base  when  the  stripper  is  depressed 
by  the  downward  stroke  of  the  blanking  die.  It  will  be  seen  that  with  this 
combination  of  spring  stripper  and  knock  out  which  act  upon  opposite 
faces  of  the  material  and  work,  the  blank  will  be  kept  free  from  distortion. 

A  CLOCK  WHEEL  DIE  FOR  THE  SUB  PRESS 

The  half  tone,  Fig.  477,  and  the  line  drawing,  Fig.  478,  show  all  details 
of  a  compound  die  for  a  clock  wheel  as  manufactured  in  the  sub  press.  This 
press  is  also  of  the  arch  type  and  the  clock  wheel  is  blanked  and  pierced  to 
form  the  central  hole  and  the  five  openings  between  the  arms,  by  feeding 


340 


PUNCHES  AND  DIES 


the  strip  of  stock  through  the  press  between  the  arched  sides  of  the  housing. 
The  wheel  produced  is  3  in.  in  diameter. 

In  referring  to  the  various  members  of  this  set  of  tools  the  same  letters 
are  used  on  both  engravings  for  purposes  of  identification.  Thus,  A  is  the 
housing  which  in  Fig.  477  is  shown  removed  from  the  base  B  to  allow  the 
punch  and  die  parts  to  be  taken  out;  C  is  the  blanking  die  for  cutting  out 
the  wheel,  and  D  the  blanking  punch.  The  latter  fits  over  the  spider 
shaped  piercing  die  E  whose  five  arms  define  the  edges  of  the  triangular 
openings  punched  out  by  piercing  punches  F  to  form  the  five  arms  of  the 
wheel.  These  piercing  punches  are  built  up  of  five  blocks  of  tool  steel 
finished  externally  to  a  taper  form  of  shank  to  fit  into  a  tapered  seat  bored 
and  ground  in  the  holder  G.  The  holder  is  also  ground  externally  to  a 


FIG.  478.  —  Construction  of  sub  press  with  compound  clock  wheel  dies 

slight  taper  to  fit  a  corresponding  taper  in  the  lower  end  of  the  plunger  H. 
Fillister  head  screws  and  dowels  are  used  to  secure  the  piercing  punches 
in  their  holder  and  the  latter  is  held  by  similar  devices  in  the  plunger.  The 
holder  further  carries  the  small  piercing  punches  ///  (three  in  number) 
which  are  located  at  the  center  for  piercing  the  three  holes  in  the  blank. 
The  upper  dies  are  provided  with  the  spring  actuated  knock  out  ring 
K,  K',  and  the  lower  tools  with  the  spring  controlled  stripper  L.  The 
knock  out  ring  K  is  operated  by  pins  M  extending  upward  to  thrust  plate 
N,  and  the  five  armed  center  of  this  knock  out  which  is  indicated  at  K'  is 
similarly  acted  upon  by  other  pins  abutting  against  the  plate  N  above. 
This  pressure  plate  is  backed  up  by  four  stiff  square  section  coiled 
springs  0  which  are  confined  in  seats  between  plate  N  and  the  top  plate  P, 
the  latter  being  adjusted  as  required  to  regulate  the  spring  pressure,  by 
means  of  the  headless  screw  tapped  through  the  button  at  Q. 


THE  SUB  PRESS  AND  ITS  DIES 


341 


The  various  minor  details  such  as  screws,  small  springs,  and  dowels 
are  all  shown  clearly  in  the  two  engravings  and  no  special  reference  to 
these  parts  is  necessary. 

SUB  PKESS  TOOLS  FOR  A  CLOCK  FRAME 

Another  interesting  sub  press  equipment  for  making  a  clock  frame  is 
illustrated  by  Fig.  479.  This  view  shows  the  work  in  the  foreground,  also 
a  smaller  piece  which  is  attached  to  the  frame  and  which  is  made  at  the 


FIG.  479.  —  Sub  press  with  details  of  dies  for  clock  frame 

same  time,  by  blanking  it  from  the  material  between  the  two  projecting 
arms  of  the  frame. 

The  frame  blanked  and  pierced  is  shown  at  A  and.  the  smaller  piece  of 
work  at  B.  The  blanking  die  C  is  made  to  be  attached  to  the  lower  end  of 
the  plunger  D  and  the  blanking  punch  E  is  fitted  to  the  base  F.  The  pierc- 
ing punches  are  carried  by  the  same  holder  as  the  blanking  die  C,  and  the 
stripper  and  knock  out  for  this  die  and  the  piercing  punches  is  made  as 
shown  at  G.  The  stripper  for  the  blanking  punch  E  is  shown  at  H  and  the 
springs  and  screws  for  both  G  and  H  are  seen  at  the  front  and  side  of  these 
two  members.  In  the  same  group  will  be  noticed,  also,  the  knock  out  pins 
I  and  the  pressure  springs  J.  The  two  adjustable  stock  gages  or  guides 
are  represented  in  position  at  K.  The  manner  in  which  these  parts  as- 
semble in  the  plunger  and  base  will  be  understood  from  the  foregoing  and 
from  the  sectional  views  of  the  other  dies  which  have  already  been  described. 


CHAPTER  XV 
PUNCH  AND   DIE   STANDARDS 

The  illustrations  and  tables  in  this  section  cover  various  standards  for 
punch  and  die  parts,  die  shoes,  punch  holders,  guide  pins  or  pillars,  etc. 
They  are  all  representative  of  the  practice  of  well-known  manufacturers 
who  make  extensive  use  of  press  tools  of  different  classes  and  they  should 
therefore  be  of  direct  service  to  many  shops  and  to  individual  die  makers 
and  draftsmen  employed  where  this  class  of  material  has  not  as  yet  been 
standardized.  Their  adoption,  in  whole  or  in  part,  according  to  require- 

Open_  Punch  &  Die  Blocks  Heavy  Pattern  Die  Blocks 


FIG.  482 
Punch  for  Heavy 

Pattern 
Die  Blocks 


FlCf4Sl 

FIGS.  480-482.  —  Standard  punch  and  die  blocks 

ments,  will  go  far  toward  simplifying  the  laying  out  of  press  tools  and  their 
construction  in  the  shop.  Furthermore  such  standards  will  enable  the 
special  work  of  the  pattern  shop  to  be  materially  reduced. 

The  drawings  and  tables  are  largely  self-explanatory  and  only  the  brief- 
est reference  is  necessary  in  the  text. 

The  sketches,  Fig.  480  to  482,  show  the  standard  plain  open  punch 
holders  and  die  blocks  used  by  one  of  the  principal  manufacturers  of  cal- 
culating machines.  The  majority  of  press  tools  in  this  shop  are  of  the 
pillar  type,  and  Figs.  483  to  486  inclusive,  cover  dimensions  for  the  head 
and  base  as  well  as  the  guide  pins  or  pillars. 

342 


PUNCH  AND  DIE  STANDARDS 


343 


The  proportions  of  blanking  dies  proper,  strippers,  pressure  pads  and 
nests  for  shaving  dies  are  given  in  Figs.  487  to  490. 

In  Figs.  491  to  494  are  shown  the  dimensions  of  punch  holders  and  die 
shoes,  also  the  scrap  choppers,  adopted  by  a  prominent  typewriter  factory. 

The  tables  and  sketches  reproduced  in  Figs.  495  to  499  show  details 
developed  from  tools  used  in  different  shops  manufacturing  a  variety  of 


FiG.483 

FIG.  4  84 
FIGS.  483-484.  —  Standard  parts  for  pillar  dies 

work,  including  automobile  parts,  small  electric  motors,  mailing  machine 
parts,  etc.  The  punch  and  die  holders  in  Fig.  495  are  a  development  of 
the  four-post  type  which  were  often  found  to  cause  difficulty  through  the 
front  pins  coming  in  the  way  of  the  operator.  In  most  cases  the  dies 
equipped  with  two  guide  pins  give  as  satisfactory  results  as  where  there 
are  four  and  the  two-post  type  are  considerably  easier  and  more  economical 
to  make.  The  patterns  for  these  holders  are  so  made  that  they  can  be 
used  in  pairs  and  the  two  castings  lined  up  for  boring  together.  The  usual 
practice  is  to  face  'off  both  castings,  clamp  them  together  in  the  milling 
machine  and  bore  both  parts  to  a  standard  plug  gage.  Type  A,  Fig. 
495,  is  used  for  general  work  and  Type  B,  Fig.  496,  is  adapted  especially 
for  round  work. 


344 


PUNCHES  AND   DIES 


No.3  Pillar  Press 
with  Shank 


No.4  Pillar  Press 
with  Shank 


Fic.485 

FIGS.  485-486.  —  Standard  parts  for  pillar  dies 


o 

c 

o. 

0 

D 

O 

f 

p 

A=3  For  Nos.l&2  Pillar  Pressure 

0 

o 


o 


o 


Fig,  487     Die 


Fig.  483     Stripper 


, 

!    v  to  ft  Thick 


^A=H"    ,,-ForBkelton 


Pads  with  several 
Openings 


Nest  r  .  Clearance  -%"  Thickness  of.Blank 

Xest^ 

havi 
-Die 


W.  Shaving 

I    I 


Fig.  489   Pressure  Pad  openings  Fig.  490 

FIGS.  487-490.  —  Pressure  pad  and  nest  details 


PUNCH  AND  DIE  STANDARDS 


345 


LI 


m 

li 


H 

K§ 


STANDARD  PUNCH  HOLDERS 


FIG.  491 


84 


84 


11 


14 


15 


165/8 


10 


124 


13 


31/4 


44 


44 


m 


m 


m 


14 


134 


134 


134 


13/4 


134 


23/4 


STANDARD    DIE    SHOES 


414 


534 


104 


74 


5* 


104 


104 


94 


12 


8% 


94 


12 


Tff 


84 


634 


94 


12 


10 


11 


94 


13 


m 


14 


m 


14 


14 


_8%_ 


104 


12 


12 


44 


15 


m 


15 


134 


_54_ 


20 


414 


19 


21 


165/8 


20 


224 


14 


STANDARD    SCRAP   CHOPPER 

- 


W=  Width  of  Stock 
= Thickness  of  Stock 

Note  :  -  The  Die  Shoe  Is 
Bolted    to    the    Press 
Bed    Thru.  Two   Holes. 
These  Two    Holes   are 
the    Distance    A  (  See 
Charts    above )     From 
Center    to    Center. 


4H 


For  3/32   Stock  or 
under  use    15/so — ' 


FIG.  494 


FIGS.  ,491-494.  —  Standard  die  shoes  and  punch  holders 


No. 


STANDARD  PUNCH  HOLDERS    (TYPE 
CAST  IRON 


3^2 


4* 


1044 


10 


12 


14 


ie 


10 


m. 


2H 


2H 


m 


m 


M- 


STANDARD   DIE  HOLDERS    (TYPE  A) 
CAST  IRON 


No. 


K_ 


3^2 


10 


m 


2% 


14 


16 


10 


20 


2V? 


FIG.  495.  —  Punch  and  die  standards 


STANDARD  PUNCH   HOLDER       iTYPE 
CAST  IRON 


TTT/-J        A.QR     


9/l« 


PUNCH  AND   DIE  STANDARDS 


347 


The  guide  pins  in  Fig.  497  are  designed  for  use  with  blanking  and  pierc- 
ing dies  and  are  used  in  connection  with  the  bushings  in  Fig.  498.  It  will 
be  noticed  that  the  pins  and  bushings  are  both  ground  for  a  press  fit  in 
the  same  size  of  hole  and  that  the  small  end  of  the  pin  is  ground  to  a  sliding 
fit  in  the  bushing  of  the  corresponding  number. 

The  guide  pins  in  Fig.  499  are  intended  to  be  used  without  bushings 
and  are  usually  employed  in  forming  dies  or  in  cutting  dies  where  the  num- 
ber of  pieces  to  be  produced  will  not  warrant  the  making  of  bushings. 


oe  , 

Shut-Higlit-Less— f- 
Pins -Tool  Steel  Hdii  &  Grind 


FlG.  49  7 


Fic.499 


FIG.  49  8 
FIGS.  497-499.  — •  Standard  guide  pins  and  bushings 


STANDARDIZING  A  LINE  OF  TYPEWRITER  TOOLS 

The  engravings  that  follow  show  the  standards  adopted  by  a  type- 
writer manufacturer  for  use  in  a  line  of  presses  made  up  of  Nos.  19,  20  and 
73i  Bliss  and  Nos.  0  and  75-D  Stiles  machines.  In  Figs.  500  to  502  are 
illustrated  the  standards  for  the  Stiles  No.  0  press.  The  construction 
drawing,  Fig.  500,  shows  the  tools  assembled  and  it  will  be  noticed  that 
guide  posts  and  bushings  are  used  on  all  of  these  tools  making  each  outfit 
practically  a  pillar  sub  press. 

In  Figs.  503  to  506  are  shown  the  equipment  for  the  No.  19  Bliss  press. 
The  shoe  and  punch  holder  for  this  press  are  made  in  six  sizes.  The  punch 
holders  are  shown  in  Fig.  510  and  are  the  same  as  those  used  on  the  No.  20 
press.  In  Fig.  506  is  shown  the  planing  for  all  the  gates  for  No.  19  presses 
and  also  the  key  for  holding  the  punch  holders  in  the  gate. 

The  standards  for  the  No.  20  press  are  given  in  Figs.  507  to  514.  There 
are  two  combinations  of  standards  for  this  size  of  press-;- one  in  which 
the  guides  are  on  the  center  line  of  the  press  side  wise,  and  the  other  where 
the  guides  are  placed  one  in  front  and  the  other  in  the  rear  of  the  center  line 
of  the  press. 

As  Nos.  19  and  20  presses  are  most  in  use  here,  standard  die  blanks  are 
carried  in  stock  rough  planed,  and  they  are  finished  planed  as  required  to 
suit  specific  conditions.  In  many  cases  rectangular  blanks  are  employed, 
these  being  screwed  into  place  without  the  aid  of  keys.  The  bolster  plate 
and  the  standard  opening  in  the  bed  of  the  press  are  shown  in  Fig.  513. 

In  Figs.  515  to  520  are  illustrated  the  standard  holders  for  the  No. 


348 


PUNCHES  AND   DIES 


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PUNCH  AND  DIE  STANDARDS 


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PUNCH  AND  DIE  STANDARDS 


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PUNCHES  AND  DIES 


PUNCH  AND  DIE  STANDARDS 


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354 


PUNCHES  AND  DIES 


"  1     TOOL  STEEL  (Harden  andCnnd) 


DETAIL  OF  TAPER  KCY 


Method  oFHoldmg  Punch  Holder 
in SlidecfHoJSD Stiles  Double 
PftmanPress.  LowerEndof 
Slide  tvbeCastSolid,as  shewn 
and providedHith  Dovetail  Slot. 
A  taper  Key  is  used  on  RightSide 
ofSlotto  clamp  Holder  in  Place. 


FIG.  528.— Punch  holder  for  No.  75-D  press 


1— -A-~H 


:n 


TOOL  srCEL(HardenandGrind) 


*x    A 

B 

C 

D 

E 

F 

7  225' 

/7f" 

05" 

/•f#" 

/" 

1251" 

2   3* 

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I.Z5" 

1.626" 

3  1.87" 

/6?" 

CP5" 

125" 

0.75" 

I.OOl" 

4  2" 

/.T" 

0.6" 

1.44" 

I" 

1251" 

5  4.1" 

3.6" 

0.5" 

1.75" 

l.?5" 

1.626" 

FIG.  529.  — Special  bolster 
and  standard  guide 


STANMRD  GUIDE  POST.  STYLE  B  STANDARD  GUIDE  POST,  STYLE  C 

FIGS.  530-531.  —  Standard  guide  posts 


l*~  E-*I 


pi  —  rjiHT"*""" 

M_;  _irT"f 

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PUNCH  HOLDER  FOR 
SIMPLE  BLANK/NO  DIES 

STOL  CASTIN6 

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3" 

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5" 

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175 

225 

5?5 

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1.75 

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575 

£75 

BLANK/N6  PUNCH  AND  DIE 
H-- -BDicor>.~'--->\ 


DIE  BED  FOR 

SIMPLE BLANK/N6DIE 
TOOL 


SIMPLE  BLANKING  D, 
two  STfCL 


FIG.  532.  —  Simple  blanking  punch  holder,  die  shoe  and  details 


PUNCH  AND  DIE  STANDARDS 


355 


.PUNCH  HOLDtt 


0/CPROPCR- 


„  \DIESTRIPPCR 

UBBCRPAD^l^PIERCM  PUNCH  ^TRipK^ 


PUNCH  PAD  •  K~DK5H(X 

COMPOUND  BLANK/NO  AND  PIERCING  DIE 


DIE  SHOE  FOR  4* 
COMPOUNDDIE 


f/25'ff. 


m-K^T-irW        iVYI 


DIE  SHOE  rOR  5" COMPOUND  DIE 

sna.  asms 


DIE  SHOE  FOR  6" COMPOUND  DIE 
STKL  CASTING 


FIG.  533.  —  Compound  die  shoes 


356 


PUNCHES  AND  DIES 


73^  press.  These  holders  are  made  in  three  different  styles  of  one  size 
each  to  suit  varied  conditions.  In  Figs.  521  to  528  are  represented  the 
standard  punch  and  die  holders  for  the  No.  75-D  Stiles  double  pitman 
press.  These  require  no  description. 

The  standard  guide  posts  and  guide  bushings  are  illustrated  in  Fig. 
529  and  two  other  forms  of  guide  posts  are  shown  in  Figs.  530  and  531. 

SIMPLE  AND  COMPOUND  DIE  STANDARDS 

The  following  tools,  Figs.  532  to  536,  were  developed  in  a  factory  en- 
gaged on  small  press  work.  The  drawings  are  given  in  detail  and  are  self- 
explanatory.  The  dies  in  Fig.  532  are  of  the  simple  open  type;  those  in 


$25" 


r?r  ••    •  !ifcg;rr?    \A 

-•-  — -  A-^7-"—  -J  0575' 


PUNCH  HOLDER  FOR 
COMPOUND  DIES 

ST01CASTIN6 


3* 

'  V 

3 

61 

A 

3?5 

4.?5 

525 

6S5 

6 

3J75 

45 

5.5 

65 

C 

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ass 

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025 

D 

16& 

4.5 

5.5 

675 

E 

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U37 

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G 

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M 

1.5 

1.75 

2 

2375 

J 

0675 

1 

t/25 

1 

PUNCH  STPIPPCRFO* 
COMPOUND  Of  £ 

MILDSTCCL 


3* 

A 

51 

6* 

A 

J 

4 

5 

6 

B 

/ 

1.5 

2 

25 

C 

W 

1.062 

1375 

175 

FIG.  534.  —  Punch  holder  and  stripper  for  compound  die 

the  other  drawings  are  of  compound  tools.  All  parts  are  kept  in  stock  and 
are  drilled  together  for  screws  and  dowels.  The  shanks  and  bolt  lugs  are 
of  course  made  to  suit  the  press. 

LOCATIONS  OF  HOLES  IN  BOLSTERS 

It  is  often  noticed  in  press  rooms  that  bolsters  are,  drilled  indiscrimi- 
nately for  screw  holes  which  are  located  more  or  less  carelessly  to  suit 
different  dies.  To  overcome  this  and  other  disadvantages  the  system  rep- 
resented in  Fig.  537  has  been  developed  wherein  only  eight  holes  are 
drilled  and  tapped  into  the  bolster  plate. 


PUNCH  AND  DIE  STANDARDS 


357 


DIE  HOLDER  FOR 

COMPOUNDDIE 

MILD  STEEL 


3" 

4" 

5" 

6" 

A 

3 

4 

5 

6 

B 

225 

2375 

275. 

4.75 

C 

2375 

3.675 

4.625 

5625 

D 

125 

4.25 

5.25 

625 

E 

0687 

Q625 

Q562 

0562 

f 

1.437 

1.675 

2J>75 

2675 

6 

1.25 

1.625 

2J25 

2.625 

H 

QJ25 

0125 

0187 

0187 

0 

t&A. 

I.B.A 

QBA 

QBA 

FIG.  535.  —  Details  of  compound  die 


[ -i     sal!       I     I  ^n 

L:..;;V:..^!  J.  A  ^'...i^K 


!~TB 


i .  jig  j  j  i  jji  -jiii  i  i  i 

L  A 

" — A* 


DIE  FOR  COMPOUNDDIES 

TOOL  STEEL.  HAKDfNCD  AND  GROUND 


3" 

4" 

5" 

6d 

A 

J 

4 

5 

.  6 

B 

025 

aw 

Q375 

0437 

C 

1.437 

1875 

2.375 

28% 

D 

1.25 

1625 

2.125 

2.625 

E- 

OJ25 

0/25 

0187 

0107 

F 

I.RA. 

I&A. 

QBA 

0.5A 

G 

oyy 

0425 

0425 

0425 

PIEPCIN6  PUNCH  PAD 
FOP  COMPOUNDDIES 

MILD  STEEL 


3" 

4" 

511 

G 

A 

?S75 

3675 

4.625 

5.625 

B 

1.25 

1.75 

2J25 

2.625 

C 

I.B.A. 

O.BA 

QBA. 

QBA. 

D 

Q/25 

0/87 

0167 

OJ67 

PUNCH  PAD  FOP 

COMPOUNDDIES 

HILD  STEEL 


3* 

4" 

5" 

6" 

A 

3 

4 

5 

6 

B 

1187 

1.667 

2.125 

2562 

C 

1 

15 

2 

2.5 

D 

0.593 

0842 

0551 

0687 

E 

Q8IZ 

1062 

075 

1.75 

F 

0.375 

aw 

QS/2 

03/2 

G 

QI87 

QJ87 

0.187 

OJd7 

H 

0.25 

025 

0512 

QSK 

FIG.  536.  —  Compound  die  details 


358 


PUNCHES  AND   DIES 


The  tapping  is  done  through  the  bolster  so  that  no  dirt  or  punchings 
can  lodge  at  the  bottom,  but  must  fall  through,  thus  keeping  the  holes 
clear  at  all  times.  The  die  shoe  is  made  of  cast  iron  and  has  ears  at  both 
ends  with  open  elongated  slots  that  have  ample  clearance,  so  the  bolts 
enter  readily.  This  also  permits  adjustment  of  the  die  after  the  shoe  con- 
taining the  die  has  been  placed  upon  the  bolster  plate.  The  holes  are  so 
positioned  that  the  shoe  may  be  placed  either  from  front  to  back  or  from 
right  to  left  on  the  press. 

Only  two  sizes  of  shoes  are  in  use  where  this  system  has  been  developed. 
These  accommodate  4-  and  6-in.  width  die  steel  that  has  been  planed  in 


I*:  TOOL  STEEL 

'  (Harden) 
FIG.  537.  —  Die  shoe,  punch  holder  and  drill  jig 

10-ft.  lengths  with  a  10-deg.  bevel  on  each  edge  and  from  which  pieces  are 
sawed  off  to  the  lengths  required.  These  die-steel  pieces  are  held  in  the 
die  shoe  by  dog-point  tool-steel  setscrews  tha"t  pass  through  the  sides  of 
the  die  shoe  at  the  same  angle  as  the  side  edges  of  the  die —  10  degrees. 
The  4-in.  shoe  is  fastened  to  the  bolster  by  two  f-in.  special-head  screws 
in  holes  that  are  tapped  10  in.  apart  in  the  bolster,  and  the  6-in.  shoe 
by  screws  tapped  into  holes  12  in.  apart. 

The  punches  are  mounted  in  J-in.  thick  by  5-in.  wide  cold-rolled  steel 
plates  made  in  two  lengths  —  5  in.  and  9  in.  These  cold-rolled  steel 
punch  plates  are  fastened  to  cast-iron  punch  holders  of  the  same  length  by 
four  special  taper-headed  casehardened  screws,  as  shown  in  the  drawing. 
Two  dowel  pins  assist  these  screws  to  prevent  any  shifting  of  the  punch 
plate. 


PUNCH  AND  DIE  STANDARDS  359 

By  mounting  punches  in  the  cold-rolled  steel  prior  to  fastening  to  the 
cast-iron  punch  holder  it  is  evident  that  not  only  is  it  possible  to  do  more 
accurate  work,  but  also  the  shank  of  the  holder  cannot  interfere  in  the  po- 
sitioning process,  as  in  the  old-style  methods.  With  this  system  only  two 
punch  holders  are  required  for  each  press  instead  of  one  for  each  die  in  use. 
The  die  shoes  and  punch  plates  are  interchangeable  on  all  presses.  A 
drill  jig  must  be  provided,  as  in  the  drawing,  and  it  will  be  observed  that 
there  are  removable  pins  and  an  eccentric  clamp  with  which  both  sizes  of 
punch  plates  and  punch  holder  are  drilled.  The  hardened-steel  dowel 
pins  shown  are  a  driving  fit  into  the  punch  holders  and  remain  in  them  at 
all  times. 

It  has  been  learned  that  this  method  saves  over  20  per  cent  jof  the  cost 
of  making  the  punches  and  dies,  and  after  that  the  saving  in  the  press 
room  is  beyond  estimate. 


CHAPTER  XVI 


FINDING  THE   SIZE   OF  BLANKS    FOR   SHELLS   AND   OTHER 
DRAWN   AND   FORMED   WORK 

In  laying  out  blanking  dies  for  shells  and  other  work  the  die  maker 
has  occasion  now  and  then  to  do  a  little  figuring  to  find  the  area  of  different 
forms  and  to  determine  the  outside  dimensions  of  given  areas  of  circles, 
ellipses,  squares,  rectangles,  and  other  shapes.  Certain  tables  included  in 


A-  Circular  Ring 


Area  =  Total  Area 
Minus  Area  of    A 


B  -    Sector  of  Circle          C~  Segmeuf  of  Circle      D  -  Segment  of  Circle 


To  Find  Area     B  ' 

Divide  360° by  Arc     B 

And  Divide  Total  Area 

of  Circle  l.j  Result 


less  than  Semi-Circle     Greater  than  Semi-Circle 

To  Find  Area ;  First  To  Find  Area ;  First 

Find  Area  of  Sector  Find  Area  of  Sector 

and  Area  of  Traingle    G'  and  Area  of  Tringle    D  ' 

then  Subtract  Latter  from  Sector       then  Add  the  Two  A* 


Area  of  Tringle   =•   Base 


Area  of  Convex  Surface 
of  a  Oone  =  Circum- 
ference of  Base  x  Half 
the  Slant  Eight 


Area  of  a  Sphere 
=  Square  of  Diameter  x  3.1416 


Area  of  an  Ellipse 
•=  Product  of  its  Axes 
Times  .7854  or 
AxBx   .7854 


FIG.  538.  —  Plane  surfaces,  and  cones  and  spheres 

this  chapter  will  be  of  assistance  in  the  finding  of  shell  blank  diameters. 
Before  takng  these  up  for  consideration  a  few  facts  relative  to  the  com- 
puting of  areas  and  dimensions  of  circles  and  other  regular  figures  will  be 
referred  to. 

Table  14,  page  370,  is  a  list  of  simple  rules  for  finding  the  various  dimen- 

360 


SIZE  OF  BLANKS  361 

TABLE  14.    RULES  FOR  FINDING  DIMENSIONS  OF  CIRCLES  AND  SQUARES 


To  find 

Having  given 

Rule 

Circumference 

Diameter 

Multiply  diam.   by  3.1416    or  divide 

diam.  by  0.3183. 

Circumference 

Area 

Divide  area  by  0.07958  and  find  square 

root  of  quotient. 

Circumference 

Side  of  an  inscribed 

Multiply  side  (A)  by  4.443. 

square  (A) 

Circumference 

Side    of    square    of 

Multiply  side  (C)  by  3.545. 

equal  area  (C)- 

Diameter 

Circumference 

Multiply  circumference  by  0.3183  or 

divide  circumference  by  3.1416. 

Diameter 

Area 

Divide  area  by  0.7854  and  find  square 

root  of  quotient. 

Diameter 

Side  of  an  inscribed 

Divide  side  (A)  by  0.7071  or  multiply 

square  (A) 

side  (A)  by  1.4142. 

Diameter 

Side    of    square    of 

Multiply  side  (C)  by  1.1284  or  divide 

equal  area  (C) 

side  (C)  by  0.8862. 

Radius 

Circumference 

Multiply  circumference  by  0.15915  or 

divide  circumference  by  6.28318. 

Area 

Circumference 

Multiply  tli,e  square  of  the  circumfer- 

ence by  0.07958. 

Area 

Diameter 

Multiply  the  square  of  the  diameter 

by  0.7854. 

Area 

Radius 

Multiply  the  square  of  the  radius  by 

3.1416. 

Area 

Circumference    and 

Multiply   the   circumference  by  one- 

diameter 

quarter  the  diameter. 

Side  of  an  inscribed 

Diameter 

Multiply  diameter  by  0.7071. 

square  (A) 

Side  of  an  inscribed 

Circumference 

Multiply  circumference   by  0.2251    or 

square  (A) 

divide  circumference  by  4.4428. 

Side  of  a  square  of 

Diameter 

Multiply  diameter  by  0.8862  or  divide 

equal  area  (C) 

diameter  by  1.1284. 

Side  of  a  square  of 

Circumference 

Multiply  circumference  by  0.2821   or 

equal  area  (C) 

divide  circumference  by  3.545. 

362  PUNCHES  AND   DIES 

sions  and  the  areas  of  circles  and  for  determining  the  relations  between 
circles  and  squares  either  inscribed  or  circumscribed.  Fig.  538  includes 
in  diagrammatic  form,  various  plane  figures,  the  areas  of  which  the  die 
maker  has  to  compute  occasionally,  and  also  covers  simple  rules  for  finding 
the  surface  areas  of  cones  and  spheres.  The  ellipse,  the  triangles,  and  the 
cone  and  sphere  have,  often  to  be  worked  out  for  surface  areas  for  work 
which  is  to  be  formed  or  drawn  and  it  will  be  found  convenient  to  have  the 
simple  rules  available  for  making  the  necessary  calculations.  The  rules 
in  Table  15  and  Fig.  538  are  self-explanatory.  In  the  table  they  are  so 
arranged  that  with  any  part  given,  the  required  part  or  dimension  can  be 
found  at  once  by  following  the  rule  in  the  third  column. 

TABLES  FOR  SHELL  BLANK  DIAMETERS 

Table  15  has  been  computed  by  the  E.  W.  Bliss  Company  for  approxi- 
mate diameters  of  blanks  for  shells  from  J  in.  diameter  by  J  in.  high,  to 
12  in.  diameter  by  12  in.  high.  These  pages  of  tables  should  be  found  of 
service  for  blank  calculations.  It  will  be  seen  from  the  footnote  that  shells 
in  the  table  are  figured  with  sharp  corners  at  the  bottom  and  diameters  of 
shells  are  taken  from  the  center  walls.  These  blank  sizes  are  approximate 
only  but  they  will  be  found  a  guide  for  the  purpose  intended.  Necessarily 
they  do  not  include  any  allowance  for  stretch  of  metal  and  they  are  figured 
without  reference  to  the  thickness  of  the  material.  The  formula  used  in 
the  computations  is  given  in  the  footnote  and  will  be  found  useful  in  making 
calculations  for  other  sizes  of  work  not  within  the  range  of  the  tables. 


SIZE  OF  BLANKS 


363 


J 
'-i. 


02 


;w 

B     S3 


II 
I5 


O    OO    <M    CO 


OO    <M 

t"-     1-H 


S8S9S8$iH 

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00    CO    CO    O    CO    CO  00 

^H    CM    CM    CO    CO    CO  CO 


§CMi— IO  ^OOCM^Ot^-OOOO  OOt^-CO-rHCMOOO 

05CM10  t5.0>CN|-*COOOOCM  TjHCOOOOS:5!S 


S  S  §  § 


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gOO  OS  OO  -3;  OO     ~H  CO  "5  1C 
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^H  OOO«C<MO5COCMOO 

l>-  OSO<M-«<»Ot-asO 


CM    OO    00    CO    O    •*  COb-OCt-t^lO^CM  O5COCOOCOCMOO-* 

U5    OO    i-l    •*!<    t-~    OS  i-HCO«5t^a>rHCO«5  COOOO<MCO»OCOOO 


'-H'-HCMCMCMCM  CMCOCOCOCOCO^'*! 


S5  fe  S  S  5 


S  S  fe  8  S 


S  S  5  S  S  S  S  S 


lOO^lOkO  ^COi— tOOCOCMOOT^  OCO^-HCO'-HCOOlO 

>OOOOCMTt<  C6000^CO>OCOOO  S^HCO-*«Ot^050 


SS  S  §  2 


IS  59  S  8  8  S      93$S3S$$ 

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Os-*iOOO500CO  r»<i-ioO^*<O>OOCO 

,H'  ^!  ^  _H-  ^J  e<J        cd  IN  ci  <M'  eo  ffo  co  eo 


S  S  S  S  gg  S 


S8  S  8  §  8  S 


eocoeoeoco«o«oco 


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364 


PUNCHES  AND   DIES 


e»  S?  &  ST  &  c¥  c?  w 


00    CO    CO    <-<    U3    CO 

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O    O    »-     rt    i- 


GO 


55  8  S  S  S8  § 

CO    CO    -^  i    "5    «O    «5 


SO     05     ^H     O5     CO  Tt* 

00    CO    05    CO    00  <M 


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« 


§  (5 


5* 

Sa 


1 1 


c<    co  •«*<         "    «s 


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gg  8  88  S  S   5S 

co  ec i  T»<  Tt i  us    ic 


O5O5C35O5 


«O    t^    t>-    CO     •<*<     CO 
0    <N    t^    (N    «0    0 


<o  10  3;  oo 

"5    I-H    »    O 


00  OO  00  O5 


«o  co  o  <M  o  eo    o 

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<N    CO    CO    CO    rji    M<  1C 


o?  58  oo  S5  £; 

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c<i  c<i  co  co  co 


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cococo'coeot^t^i^ 


sr 


SIZE  OF  BLANKS 


365 


is. 

00  W 


PQ 


. 

a? 


<»       rt 
1      03 


Diameter  of 
shell 

••*««**  -««« 

o  3T  d?  3?  2?  &  IS  3? 

» 

COiOl^OOOCSCO^O              t^-OOOC^COiOOCO 
t^-t^t--    t^-OOOOOOOO            OOOOOSOOidOiOi 

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ptfH 

CO 

^_??^§S8g2^      5  S  S  S  a  §5  Sg  S 

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COt^t^t^t^b-t^OO             OOOOOOOOOOOSO5O5 

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CO 

KS5S8S5SS83S       8  S  S  5  S  g  S  g 

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ST 

^  s  s  §  a  g  ss  s     s  s  g  s  K§  s  ss  g 

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£ 

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gS5355SgSg      ^^SSggggJ 

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000000000005050. 

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t^oooooooooooooo 

a 

OOCOt-C^CO-^05             COt--H«5C3JCOt-0 

^00(MiOOS<NC001 

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T^CO^COt^OOO                rtCO^»Ot^0005r-l 

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00    00 

* 

gSS^^SKS      82£§3co8§ 

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t>"  *-*5i 

BlOO 

g  S  S  !8  S8  S  SB  S      S  8  S  3  S  S  8  S 

« 

feg^S^SS^      §§SS5S§S 

ol  S  £  §5  S5  S|  £>  S 

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eo«wS?«MMW        T«  ^?  ^7  3?  $  5S?  5?  * 

.,„„„ 

366 


PUNCHES  AND   DIES 


I 

"S 

ll 

1 

TABLE  15  (Continued}.  —  APPROXIMATE  DIAMETER  OF  BLANKS  FOR  SHELLS 
From  3  in.  Diameter  by  4  in.  High  to  5|  in.  Diameter  by  12  in.  High 

Height  of  shell 

CM 

wSg^^oSS      3co§~coSo3S      cSSSSScoSS 

3 

2S8S3S88      3SSSSSSS      &33888K3 

s 

OO'HCoSoO^HCOCO 

OOOCOiOt^-OSCS-^             COOOOC^)iOt>-OirH 

o 

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o 

dddi^ll  »»««2:is  Ii:ss!s2 

0? 

2S3222sS  SsSsS;::  :5°2:!s! 

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ei  N  w  c^  «^  «  «  TJ!         ^^^^«5^^^ 

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oo 

d  o  o  o  i-i  ^  »-i  i  i-J 

<M-*tDOOO<M^tl             COt^Cii-lCOiOt^OS 

CM'  CM'  <M'   exi  CM   co  co   co         co  co  co   -^   •*  -^  -<*<•* 

ff 

5522152!  !523222!  2:!^^: 

- 

g 

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CO»OI>'O5r-icCi"5I>- 

O5    OJ    O>    O>    O    O    O    O 

,§S§?SS8SS      ^85S§S§§SS 

CO 

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O     O     O     rH     ^H     ~H     rt     ^H               CNJ     C<1     CNJ     CNI     (M     <M     CO     CO 

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OSO^rHOOWCNIOO             .OtMOOTt-gOtNOO 

C55O5OSOOOOO               O^'^^H^H'-I'-H<N 

$ 

SSS35SS8S 

t^-OOOOOOOOOOO5O 

$ 

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„ 

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t^t^i>-oocooocooo 

•o 
Q 

SIZE  OF  BLANKS 


367 


H 

3 


•8. 

ii 

1 

co  co*  co  co         i>.  t^  !>T  i?-         000000*00 

J" 

«!•* 
CO 

a  saq     sgg£     s  a  s  3 

8SSS        S§^2         o^SK        8 

* 

8  8  2$  88      2  3  g  8      £  3  §3  2 

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1 

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ISS^          2SI^          355us          1 

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osososos     2222     dddd 

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T-H    <M    <M    05             C<j    CO    CO    CO             CO    ••*'    -*'•*'             •*' 

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COUSOOO             COCOOO^H             COCOOS^H 

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9883      388S.SSSS      S 

03 

03 

3 

odoooooo         osososos         2222 

^  Z3  ^  Z2       23  22  ^  2       co  cd  co  •*'   ^  -^ 

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t^ododoo'         oo'ososos         oooo' 

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368 


PUNCHES  AND  DIES 


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Diameter  of 
aiiaii 

1 
i 

SIZE  OF  BLANKS 


369 


In  making  different  calculations  for  blanks  of  various  dimensions,  com- 
plete tables  of  circles  with  areas,  and  circumference  are  extremely  useful, 
and  indispensable  data  of  this  kind  with  other  tables  on  stock  thicknesses 
by  gages,  weights,  etc.,  will  be  found  in  the  American  Machinist's  Hand- 
book worked  out  to  the  smallest  detail  for  convenience  of  reference.  It  is 
taken  for  granted  that  the  above  book  is  already  in  the  hands  of  the  reader 
of  this  volume  and  it  is  therefore  unnecessary  to  reproduce  in  this  treatise 
the  tables  referred  to  which  with  other  valuable  reference  matter  pertain- 
ing to  the  subject  runs  to  many  pages  in  extent.  A  table  of  stock  thick- 
nesses by  the  most  commonly  used  gages  is,  however,  given  in  this  book 
on  page  35,  Chapter  II. 

LAYING  OUT  A  BLANK  FOR  A  RECTANGULAR  DRAWN  SHELL 

To  eliminate  some  of  the  trial  blanks  in  making  dies  for  drawing  rec- 
tangular boxes  the  following  method  is  suggested : 

Let  us  assume  that  the  box  at  C,  Fig.  539,  is  required  and  we  wish  to 
determine  the  size  and  shape  of  the  blank.  We  draw  the  center  lines  B, 


FIG.  540 


FIG.  541 


FIGS.  539-541 


Fig.  540,  after  which  the  bottom  of  the  box  is  laid  out  as  at  C;  then  lay 
out  the  outer  box  D,  the  distance  from  C  to  D  being  slightly  less  than  the 
1J  in.  specified,  say  1J£  in.  Draw  line  E  through  the  corners  of  C  and  D 
and  scribe  the  required  radius  of  one  inch. 

In  the  American  Machinist  Handbook  we  find  that  for  a  shell  1  in.  in 
diameter  and  1J  in.  high  the  blank  diameter  given  is  2.65  in.,  which  is  ob- 
tained from  the  formula 

D  =  Vd(d  +  4ft) 


370  PUNCHES  AND  DIES 

where 

D  =  Blank  diameter, 
d   =  Diameter  of  finished  shell, 
h   =  Height  of  finished  shell, 

or  it  may  be  expressed  as  follows:  Add  diameter  of  finished  shell  to  four 
times  its  height;  multiply  this  result  by  the  diameter  of  the  finished  shell 
and  extract  the  square  root  of  the  product;  this  root  will  be  the  required 
blank  diameter. 

With  a  radius  equal  to  one-half  this  amount  scribe  an  arc  at  each 
corner  as  at  F,  and  connect  this  arc  to  the  outer  lines  D  by  curved  lines, 
as  shown,  the  radius  of  which  can  be  made  several  times  larger  than  the 
corner  radius  of  finished  shell. 

After  this  is  done  we  have  a  real  trial  blank,  a  duplicate  of  which  should 
be  made  in  case  alterations  are  necessary. 

BLANKS  FOR  TAPERED  SHELLS 

From  the  same  source  referred  to  above,  we  have  the  formula  for  a 
tapered  shell  blank  as  follows:  Fig.  541  shows  a  taper  shell  with  small 
diameter  of  finished  shell  represented  at  d,  large  diameter  at  d'  and  blank 
diameter  D,  and  height  h.  The  formula  is  then  D  =  2  hV(d  +  d')  +  & 


CHAPTER  XVII 
LAYING   OUT  AND   MAKING  TEMPLETS  AND   DIES 

There  are  various  methods  of  laying  out  dies  and  boring  and  machining 
to  correct  outline.  The  method  selected  will  vary  with  the  experience  of 
the  die  maker,  the  equipment  of  the  tool  room  where  he  is  employed,  the 
class  of  work  for  which  the  die  is  to  be  used,  and  the  corresponding  degree 
of  accuracy  to  which  the  die  must  be  held  in  its  production. 

The  methods  of  one  shop  may  seem  crude  when  compared  with  the 
practice  elsewhere;  on  the  other  hand,  the  methods  of  the  more  exacting 
tool  room  may  seem  unnecessarily  refined  to  those  employed  in  the  former 
shop.  Both  grades  of  workmanship  are  undoubtedly  justified  in  the 
results  demanded  of  the  two  distinct  classes  of  shops,  and  the  products  of 
two  press  rooms  are  legitimately  of  different  grades  of  accuracy,  just  as 
the  work  produced  in  the  milling,  turning  and  other  machine  departments 
of  different  plants  may  justifiably  vary  in  respect  to  the  limits  adhered  to 
in  accordance  with  the  general  character  of  the  article  manufactured. 

Quality  and  quantity  of  output  are  naturally  the  two  important  fac- 
tors in  determining  the  degree  of  nicety  to  which  a  set  of  press  tools  should 
be  held.  The  same  factors  are  the  determining  ones  in  fixing  the  type  and 
design  of  the  tools  as  well.  Without  accurate  dies,  accurate  press  work 
need  not  be  expected,  and  with  tools  of  improper  design  and  construction 
satisfactory  results  in  the  direction  of  high  production  and  low  cost  of  up- 
keep are  out  of  the  question. 

A  great  deal  of  judgment  is  often  necessary  to  fix  the  standard  to 
which  a  set  of  tools  should  be  held.  A  small  lot  of  punched  parts  may  be 
as  exacting  in  the  limits  of  accuracy  demanded  as  a  run  of  work  involving 
a  million  pieces.  Yet  where  the  latter  case  would  justify  the  expenditure 
of  any  necessary  amount  of  time  and  care  in  the  production  of  the  tools, 
the  same  expense  for  the  dies  for  a  small  total  output  might  mean  nothing 
better  than  a  very  heavy  loss  on  the  part  of  the  tool  room.  Such  a  con- 
dition might  suggest  the  application  of  some  other  means  altogether  for 
the  handling  of  the  work,  thus  eliminating  the  making  of  the  press  tools 
entirely  for  this  particular  article. 

While  there  are  certain  classes  of  expensive  machines  made  up  very 
largely  of  press  made  members  where  the  requirements  throughout  are 
universally  conceded  to  be  exacting  and  where  only  the  closest  workman- 

371 


372  PUNCHES  AND  DIES 

ship  upon  the  part  of  the  die  makers  is  passed  by  the  inspectors,  it  is  not  the 
case  on  the  other  hand  that  all  cheaply  marketed  apparatus  is  necessarily 
produced  by  cheap  tools,  of  indifferent  degree  of  accuracy.  For  there  are 
instances  where  accuracy  of  parts  is  not  demanded  by  the  character  of 
the  completed  article  itself,  but  rather  by  its  very  cheapness  which  neces- 
sitates a  quality  of  exactness  which  will  insure  all  of  its  parts  admitting 
of  assembling  with  absolutely  no  delay  upon  the  part  of  the  bench  hands, 
for  a  few  moments  of  lost  time  at  this  point  may  more  than  eliminate  the 
narrow  margin  between  total  cost  of  production  and  the  marketable 
figure  to  which  the  completed  piece  must  be  held. 

These  conditions  have  more  than  a  little  to  do  with  the  grading  of 
work  qualities  in  the  tool  room.  The  experienced  die  maker  will  adapt 
his  methods,  so  far  as  his  equipment  permits,  to  the  requirements  of  each 
particular  set  of  dies,  if  he  is  desirous  of  seeing  the  tools  progress  with  the 
greatest  degree  of  despatch  commensurate  with  the  special  necessities  of 
each  job  as  it  comes  to  his  bench.  And  this  does  not  mean  that  he  will 
necessarily  turn  out  at  any  time  what  might  be  called  a  "sloppy"  set  of 
dies,  but  rather  that  he  will  always  make  the  very  best  tools  required  for 
any  given  grade  of  work  and  vary  his  methods  and  degrees  of  refinements 
to  harmonize  with  the  results  he  wishes  to  attain. 

The  process  of  locating  and  boring  holes  in  dies  and  punch  plates  has 
been  developed  along  parallel  lines  to  the  similar  operations  involved  in 
the. production  of  high-grade  jig  work.  The  use  of  the  vernier  height  gage 
in  laying  off  work  centers  and  outlines,  the  application  of  the  well-known 
button  and  master  plate  methods,  the  use  of  verniers  and  micrometer  heads 
on  milling  machines  and  various  systems  of  end  and  distance  gages  have 
all  been  found  of  great  value  in  the  construction  of  press  tools.  There  are 
innumerable  instances  where  such  applications  as  these  are  as  readily  made 
to  die  work  as  to  the  more  commonly  known  classes  of  jig  work  where  some 
one  or  other  of  the  above  methods  is  so  frequently  resorted  to  for  the  lo- 
cating of  hole  centers  at  exact  distances.  Then,  too,  the  universal  dividing 
head  for  the  miller  has  its  every  day  uses  on  punch  and  die  operations  just 
as  it  has  long  been  applied  to  the  numerous  problems  arising  in  connection 
with  precision  tool  work  in  general.  An  intimate  knowledge  of  the  pos- 
sibilities of  the  dividing  head  including  the  additional  flexibility  of  this 
device  which  has  been  brought  about  by  the  extension  of  differential  index- 
ing, is  becoming  an  almost  indispensable  part  of  the  die  makers  personal 
equipment. 

There  are  various  special  machines,  as  well  as  attachments  for  standard 
tools,  that  have  been  developed  for  die  making  as  also  for  general  precision 
tool  work.  In  several  instances  such  equipment  has  been  originated  spe- 
cifically for  facilitating  the  production  of  dies  alone,  although  like  many 
other  lines  of  tools  this  equipment  has  gradually  been  expanded  in  its 


LAYING  OUT  AND  MAKING  TEMPLETS  AND  DIES 


373 


usefulness  and  it  now  covers  the  necessities  of  other  classes  of  work  as 
well.  Certain  types  of  milling  machines,  slotters  and  shapers,  slotting 
attachments,  filing  machines  and  so  on  are  cases  in  point.  The  precision 
drilling  machine  has  been  found  as  invaluable  for  die  operations  as  for  jig 
plate  drilling  and  boring,  and  the  bench  lathe  with  its  milling  attachment, 
traverse  spindle  grinder  and  other  appurtenances,  has  for  long  been  one  of 
the  tools  that  the  die  maker  cannot  dispense  with. 

It  is  the  purpose  of  this  section  to  show  some  of  the  applications  of  the 
foregoing  principles  and  tools  to  the  solution  of  various  interesting  prob- 
lems of  the  die  maker. 


.ViseJans 


Hardened 

FIG.  542    FIG.  543  FIG.  544 


FIG.  545 


.  Hardened  Parallel 
'or  Straight  Edge 


V 

FIG.  548  FIG.  549 

FIGS.  542-549.  —  Simple  dies  and  templets 

MAKING  AND  USING  SIMPLE  TEMPLETS 

An  easy  and  simple  way  of  making  templets  for  use  in  connection  with 
die  work  is  illustrated  by  the  following  engravings: 

The  dies  referred  to  are  of  the  simple  piercing  and  blanking  type  com- 
monly known  as  follow  dies,  which  are  to  produce  blanks  similar  to  the 
templet  shown  in  Fig.  542.  For  this  piece  any  dimension  can  vary 
0.004  or  0.005  in. 

Several  blanks  TV  in.  thick  are  wanted  for  experimental  purposes,  one 
to  be  used  as  a  templet.  About  the  best  way  to  make  the  first  lot  by  hand 


374  PUNCHES  AND   DIES 

is  to  cut  several  pieces  of  material  to  the  proper  length  and  width  and 
clamp  them  together.  Lay  off  the  J-in.  holes  2  in.  apart  and  drill  and 
ream  them.  Large  holes  should  not  be  drilled  in  single  thin  pieces  when  a 
round  hole  is  required. 

The  next  step  is  to  make  the  gages  shown  in  Figs.  543  and  544.  The 
gage  shown  in  Fig.  543  is  for  the  f-in.  radius  at  the  ends,  and  the  flat  shown 
on  one  side  is  for  establishing  a  line  ^  in.  each  side  of  the  center,  which  is 
half  the  width  of  the  straight  part  of  the  link.  The  gage  shown  in  Fig. 
544  is  a  yf-in.  washer  TV  in.  thick  with  a  J-in.  hole  that  fits  over  the  stem  of 
the  templet,  Fig.  543,  which  should  be  g7?  in.  long.  It  requires  only  a  few 
minutes  to  make  these  pieces  and  saves  a  lot  of  bother  later.  They  should 
be  casehardened  in  cyanide  and  used  as  templets  in  filing  the  ends  of  the 
work  shown  in  Fig.  542. 

In  Figs.  545  and  546  is  shown  the  proper  way  of  holding  the  work  to 
be  filed.  This  finishes  the  model,  and  if  we  have  worked  with  reasonable 
care  up  to  this  point  we  are  ready  for  the  die. 

After  the  steel  die  block  has  been  surfaced  and  squared,  the  face  should 
be  treated  by  heating  until  a  dark-blue  color  is  obtained,  or  by  rubbing  with 
a  little  clean  waste  dampened  with  sulphate  of  copper  solution.  Another 
good  surface  for  a  layout  is  obtained  by  filing  or  grinding  off  all  tool  marks 
and  rubbing  with  emery  cloth.  The  rubbing  should  not  be  done  straight 
across,  but  around  and  around,  covering  only  a  small  portion  at  a  time. 
Layout  lines  are  easily  seen  upon  this  dull  finish. 

In  Fig.  347  is  shown  the  proper  layout  for  this  die. 

With  a  very  fine  scriber  draw  the  lines  B  and  C,  2  in.  apart,  crosswise  of 
the  steel  1  in.  from  the  center,  and  a  line  lengthwise  about  J  in.  from  the 
center.  With  the  dividers  set  to  §f  in.,  which  is  the  width  of  the  templet  at 
the  large  end  plus  TV  in.,  which  we  allow  for  scrap,  lay  off  E  and  F,  using  as 
centers  the  intersection  of  B  and  C  with  the  lengthwise  line.  The  layout 
should  always  be  reckoned  from  the  large  end  of  the  blank.  Fig.  548  shows 
a  blank  with  a  clipped  ear,  the  result  of  the  layout  shown  in  Fig.  549. 

We  could  bore  this  die  on  the  miller  without  a  layout,  but  we  would 
have  to  put  the  clearance  in  later,  so  it  is  best  to  do  it  in  the  lathe,  using 
the  compound  rest  set  for  f-degree  clearance  for  the  f-in.  holes,  and  taper- 
ream  the  |-in.  holes.  The  straight  part  in  the  middle  can  be  drilled  out  and 
finished  in  the  miller  or  shaper  with  an  extension  tool,  and  the  ^|-in.  radius 
also.  When  the  screw  holes  are  drilled  and  tapped  and  the  dowel  pin- 
holes  drilled,  the  die  is  ready  for  hardening,  after  which  it  is  ground  on 
both  sides  and  fitted  to  the  shoe. 

A  templet  should  be  marked  "Die"  on  one  side  and  "Punch"  on  the 
other,  as  an  irregular  punch  will  not  fit  the  die  if  laid  out  from  the  same  side 
of  the  templet.  In  laying  out  the  die  the  surface  marked  "Die"  should 
lie  next  to  the  steel,  using  the  other  side  for  the  punch.  As  there  are 


LAYING  OUT  AND  MAKING  TEMPLETS  AND  DIES 


375 


several  styles  of  die  shoes  and  punches,  the  workman  should  be  governed 
largely  by  the  material  furnished.  The  piercing  punch  holes  in  the  punch 
holder  are  located  by  drilling  through  the  die  from  the  back,  with  the 
blanking  punch  in  place.  The  most  important  thing  in  a  follow  die  is  to 
place  the  piercing  holes  in  proper  relation  to  the  blanking.  Then  the  die 
becomes  a  master  by  which  to  make  and  align  the  punches. 

The  dotted  outline  of  the  blank  on  Fig.  547  is  for  the  purpose  of  showing 
the  proper  layout. 

SOME  TEMPLET  TOOLS 

In  Fig.  550  some  handy  appliances  are  shown  for  use  in  connection 
with  the  making  and  application  of  templets  for  dies.  In  the  foreground 
of  this  photographic  view  is  a  scriber  A  that  is  a  most  useful  tool  for  mark- 
ing with  very  fine  line  around  the  edge  of  a  templet.  The  handle  is  J  in. 


FIG.  550.  —  Templet  tools 

diameter  drill  rod  with  a  point  inset  of  gV  in.  diameter  wire  ground  to  a 
sharp  point  that  enables  lines  to  be  scribed  at  all  points  along  a  templet 
edge  and  even  in  very  small  corners  where  the  radius  is  so  slight  as  to  make 
it  impossible  to  follow  with  anything  much  coarser  than  a  needle  point. 

The  tool  B,  with  the  short  vertical  post  that  gives  it  a  resemblance  to 
a  die  square,  is  for  finishing  the  edges  of  templets  like  the  one,  say,  at  C. 
The  base  or  block  is  about  2J  in.  long  by  J  in.  thick.  It  is  fitted  with  a 
three  cornered  post  as  shown  which  is  made  of  tool  steel  and  hardened  and 
ground  to  sharp  edges  on  all  three  corners.  This  tool  is  used  as  a  scraper 
for  removing  the  slight  burr  on  the  edge  of  the  templet  and  for  finishing  the 
edge  perfectly  square  with  the  flat  faces.  The  tool  is  held  with  the  templet 
face  resting  against  the  upper  face  of  the  block,  and  when  the  tool  is  moved 
carefully  along  the  edge  of  the  templet  it  necessarily  brings  the  edge  true 
and  square  with  the  templet  face. 


376 


PUNCHES  AND   DIES 


LAYING  OUT  AND  ROUGHING  OUT  DIES 

The  work  illustrated  in  Figs.  542  to  549  covered  the  working  out  of  a 
die  from  a  templet  where  the  main  portion  of  the  die  admitted  of  working 
out  by  simple  drilling  of  the  stock  and  finishing  out  on  the  miller  or  shaper. 
This  slot  could  in  fact  have  been  milled  from  the  enlarged  holes  already 
bored  at  the  ends,  without  preliminary  rough  drilling  if  so  desired,  the  proc- 
ess selected  depending  upon  the  relative  amount  of  time  required  by  the 
alternative  methods.  There  are  many  cases  though,  where  the  complete 
die  contour  must  be  outlined  and  blocked  out  by  rough  drilling  and  the 
various  tools  for  facilitating  this  operation  are  of  interest  at  this  point. 


FIG.  551.  —  Vernier  height  gage  used  in  laying  out  dies 

The  die  opening  may  be  laid  out  by  a  templet  as  before,  or  the  various 
working  points,  center  lines,  centers  of  radii,  etc.,  may  be  laid  off  on  the  die 
block  by  setting  up  on  an  angle  plate  as  in  Fig.  551  and  applying  the  vernier 
height  gage  as  illustrated.  With  the  die  block  planed  square  on  ends  and 
edges  and  using  a  true  surface  plate  as  shown,  the  working  lines  and 
centers  desired  may  be  laid  off  accurately  and  very  conveniently. 

If,  then,  the  die  opening  is  to  be  drilled  for  finishing  by  sha'ping,  milling, 
and  filing,  the  simple  tools  shown  below  will  be  found  of  value  in  locating 
the  series  of  hole  centers  so  that  the  drill  will  do  most  of  the  work,  leaving 


LAYING  OUT  AND   MAKING  TEMPLETS  AND  DIES 


377 


but  little  stock  between  for  removal  afterward.  There  are  different  types 
of  center  punches  for  this  class  of  work.  Some  die  makers  use  what  is 
known  as  the  spacing  center  punch,  others  prefer  the  type  of  punch  which 
strikes  the  center  for  the  drill  and  at  the  same  time  forms  a  circle  by  which 
the  punch  is  set  for  the  next  center  and  so  on.  This  punch  undoubtedly 
simplifies  the  whole  process  very  appreciably. 

APPLICATION  OF  THE  SPACING  CENTER  PUNCH 

If  the  spacing  center  punch  is  to  be  used  the  solid  type  shown  in  Fig. 
552  has  few  equals.  A  set  of  four  such  punches  with  the  punch  points 
J>  T\>  i>  and  f  in.  apart  will  cover  all  requirements  for  general  die  work. 
A  set  of  these  punches  can  be  made  by  any  toolmaker  in  a  short  time. 


FIG.  552 


FIG.  554  FIG.  555 

FIGS.  552-555.  —  The  spacing  punch  and  the  drilled  work 

To  describe  the  various  steps  from  a  piece  of  drill  rod  to  the  finished 
article,  we  will  take  for  an  example  a  center  punch  with  the  spacing  points 
J  in.  apart.  A  piece  of  drill  rod  is  cut  to  a  convenient  length  and  one  end 
is  rounded  as  at  A,  Fig.  553.  The  other  end  is  flattened  out  as  shown  at 
B.  All  the  other  stages  —  from  C  to  G  —  in  making  this  type  of  center 
punch  are  self-explanatory.  An  8-in.  mill  file  and  a  J-in.  square  file  are  the 
tools  to  be  used  for  beveling  the  flat  sides  and  the  edges,  as  at  D  and  E,  and 
also  for  filing  the  nicks.  After  this  has  been  done,  the  center  portion  left 
by  the  square  file,  as  shown  at  F,  is  filed  down.  The  punch  will  then  re- 
semble G.  The  corners  left  on  the  two  spacing  points  are  now  rounded  off 
with  a  small  file,  and  the  punch  is  ready  for  hardening.  If  made  of  drill 
rod,  it  should  be  hardened,  and  then  drawn  to  a  dark  straw  color.  A 


378 


PUNCHES  AND  DIES 


spacing  center  punch  is  used  only  to  make  a  small  impression  for  the  regular 
heavy  center  punch  to  follow,  so  there  is  no  danger  of  the  spacing  points 
breaking  off  in  use.  Where  a  set  of  spacing  center  punches  of  this  type  has 
been  made,  the  punches  should  be  stamped  on  the  stem  with  the  size  of 
drill  to  be  used  with  each  punch,  as  shown  in  Fig.  552.  The  sizes  can  be 
stamped  on  after  the  punches  have  been  hardened  and  tried  out. 

A  kink  worth  remembering  in  drilling  stock  for  parting  is  illustrated  in 
Fig.  554.  The  piece  E  is  to  be  removed  from  the  sectional  die  block  A 

by  drilling.  After  a  line  has  been 
scribed  a  safe  distance  from  the  finish 
contour  of  the  die,  in  this  case  repre- 
sented by  the  line  B,  the  drill  centers 
are  laid  out  with  a  spacing  center 
punch  and  the  impression  deepened 
with  a  regular  punch.  Every  other 
hole  C  is  now  drilled  clear  through 
the  block  A  all  the  way  around.  The 
holes  D  are  then  drilled  the  same  way, 
and  if  the  drilling  has  been  properly 
done,  the  piece  E  can  easily  be  re- 
moved by  a  few  taps  with  a  hammer. 
The  reason  for  drilling  every  other  hole 
is  to  prevent  the  drill  from  running  off 
into  the  next  hole.  A  glance  at  the  layout  in  Fig.  555  will  make  clear  the 
point  here  involved  and  will  demonstrate  that  the  only  successful  way  of 
drilling  holes  A,  B,  and  C  is  to  drill  holes  A  and  C  first  and  leave  hole  B 
for  the  last. 

As  an  actual  illustration  of  a  closely  drilled  die  with  a  minimum  of 
metal  in  the  walls  between  adjacent  holes,  the  photograph,  Fig.  556,  is 
presented  here.  Examination  of  the  die  blank  under  the  microscope  will 
show  that  only  the  thinnest  wall,  a  few  thousandths  of  an  inch  at  the  most, 
is  left  between  holes,  so  that  the  center  is  easily  knocked  out  and  very  little 
stock  left  for  finishing  down  to  the  die  outline. 

THE  CIRCLE  MARKING  CENTER  PUNCH 

With  the  spacing  center  punch  described  above  it  is  of  course  necessary 
to  draw  a  model  line,  then  a  line  as  a  guide  for  "the  punch,  which  means  quite 
a  little  additional  work  where  the  outline  is  at  all  irregular.  The  type  of 
punch  which  marks  its  own  circle  for  a  guide  is  made  as  follows: 

Put  a  piece  of  drill  rod,  0.015  in.  larger  than  the  drill  to  be  used,  in  a 
spring  chuck  in  the  lathe  and  with  a  lathe  tool  or  graver  form  a  fine  point 
in  the  center;  also  a  sharp  outer  edge,  as  shown  at  A,  Fig.  557.  Harden 
and  draw,  and  it  is  ready  for  use. 


FIG.  556.  —  Series  of  holes  in  drilling 
out  a  die  opening 


LAYING  OUT  AND  MAKING  TEMPLETS  AND  DIES 


379 


After  drawing  the  blank  outline  on  the  die  block,  put  the  sharp  edge 
of  the  punch  on  the  line  and  tap  lightly,  which  leaves  a  center  punch  mark 
and  circle  to  which  the  punch  is  set  for  the  next  hole,  as  shown  at  B. 

After  drilling,  there  is  a  web  left  between  the  holes;  to  remove  this 
make  a  drift  from  drill  rod  twice  the  diameter  of  the  drill  used  minus 


FIGS.  557-558.  —  Spacing  center  punch  and  drift 

0.015  in.;   file  or  mill  it  on  two  sides  to  0.010  in.  thinner  than  the  drill, 
round  the  other  two  sides  to  approximate  the  drill  radius,  put  a  slight  con- 


FIG.  559.  —  Circle  marking  center  punches 

cave  in  the  end,  as  shown  at  C,  Fig.  558,  harden  and  draw,  and  it  is  ready 
to  use. 

To  remove,  or  rather  separate,  the  pieces  and  at  the  same  time  remove 
the  web,  drive  the  drift  through  the  perforated  places  and  the  piece  will 
come  out  and  leave  0.0125  in.  for  finishing. 

A  set  of  these  center  punches  for  various  sizes  of  circles  are  represented 
by  Fig.  559.  These  range  from  a  size  which  will  mark  the  circle  for  a  iV 
in.  drill  to  a  size  suitable  for  a  f-in.  drill. 


380 


PUNCHES  AND   DIES 


DRILLS  AND  DRIFTS 

The  half  tone,  Fig.  560,  shows  a  set  of  spotting  drills  for  various  uses 
in  die  making,  including  the  starting  of  holes  in  drilling  out  dies  prior  to 
running  twist  drills  through. 

The  tools  in  Fig.  561  are  a  set  of  drifts  for  cutting  out  the  walls  between 
drilled  holes  as  required  in  removing  the  stock  outlined  by  the  series  of 


FIG.  560.  —  Spotting  drills 


FIG.  561.  —  A  set  of  die  drifts 

holes  inside  the  die  contour.  These  drifts  are  made  in  accordance  with  the 
experience  of  many  die  makers  who  find  that  the  wedge  shaped  section  of 
the  drift  gives  a  freer  cut  and  enables  the  drift  to  clear  and  free  itself  as 
it  is  driven  through  the  walls  between  adjacent  holes.  Most  of  these 
drifts  are  short  and  without  shanks,  being  formed  to  uniform  shape  from 
end  to  end  and  they  are  therefore  stiff  and  rigid  under  the  action  of  the 
hammer  applied  in  making  the  separating  cut. 

Some  of  these  drifts  will  be  seen  to  have  a  decided  angle  of  slope  from 
back  to  front  of  cutting  edge  and  in  this  case  they  are  adapted  for  cutting 


LAYING  OUT  AND   MAKING  TEMPLETS  AND  DIES  381 

out  where  holes  of  different  sizes  have  been  drilled  as  in  stocking  out  the 
material,  between,  say,  the  teeth  of  a  wheel  die,  where  it  may  be  possible 
to  drill  two  or  more  holes  between  top  and  root  of  tooth  with  drills  of 
decidedly  different  diameters.  Wherever  there  is  marked  reduction  in 
the  width  of  the  slot  to  be  formed,  the  sharp  wedge  sectioned  drifts  are 
extremely  useful. 

WORKING  OUT  THE  DIE  OPENING 

The  method  of  finishing  the  interior  of  a  die  after  the  stock  has  been 
removed  from  the  inside  of  the  drilled  outline  may  be  by  milling,  shaping, 
and  filing,  or  by  a  combination  of  operations  on  the  lathe,  miller,  shaper, 
slotter,  and  filing  machine.  Frequently  the  die  is  of  such  form  as  to  admit 
of  the  grinding  of  a  good  share  if  not  all  of  the  interior  after  it  has  been 
hardened.  This  may  be  done  on  the  regular  grinding  machine,  the  in- 
ternal grinder,  or  with  a  traverse  spindle  grinder,  depending  upon  the  size 
and  general  character  of  the  work. 

A  typical  example  in  working  out  the  inside  of  a  die  is  represented  by 
Fig.  562  which  shows  the  work  set  up  under  the  adjustable  ram  of  a  slot- 
ting attachment  where  the  oblong  opening  of  the  blanking  die  and  the 
half  round  portion  at  one  side  are  being  shaped  as  indicated.  .  The  head 
for  the  slotter  attachment  on  this  machine  is  adjustable  to  give  any  desired 
angle  for  die  clearance,  either  one-half  degree  or  more  according  to  re- 
quirements. The  die  is  shown  here,  however,  secured  to  an  adaptor  plate 
which  is  itself  planed  off  on  the  bottom  to  a  half  degree  slope  for  general  use 
in  machines  where  adjustment  of  the  tool  slide  is  not  possible  and  so  the 
ram  in  this  instance  is  set  in  perpendicular  position. 

ADVANTAGES  OF  THE  ADAPTOR 

This  adaptor  or  sloping  holder  for  the  die  has  been  found  a  convenience 
in  many  cases  aside  from  its  application  to  the  holding  of  dies  under  some 
such  condition  as  that  illustrated.  For  example,  when  a  die  or  punch  is 
to  be  ground  with  shear  for  facilitating  its  cutting  action  the  sloping  holder 
enables  the  work  to  be  set  up  on  the  surface  grinder  and  gives  at  once 
sufficient  angle  for  the  work  to  be  faced  to  the  requisite  angle  of  shear  as 
generally  desired.  The  half  degree  slope,  while  seemingly  slight,  amounts 
to  an  actual  slope  of  about  0.009  in.  per  in.  of  length  so  that  a  punch  say, 
7  in.  across  from  end  to  end,  would  be  ground  to  a  total  shear  of  TV  in. 
An  illustration  of  this  method  of  using  the  appliance  is  given  in  Fig.  563 
where  a  large  blanking  punch  is  seen  in  place  for  the  grinding  of  its  face 
to  the  angle  specified. 

Another  application  is  seen  in  the  instance  of  the  punch  in  Fig.  564, 
which  represents  a  case  where  a  circular  disk  or  washer  punch  is  to  be 
sheared  at  four  points  about  its  circumference.  The  work  is  indexed  about 


382 


PUNCHES  AND   DIES 


FIG.  562.  —  Slotting  out  a  die  opening 


I-    p 


FIG.  563.  —  Adaptor  for  grinding  shear  on  blanking  punch 


LAYING  OUT  AND  MAKING  TEMPLETS  AND  DIES 


383 


its  base  by  turning  the  holding  flange  and  when  passed  under  the  surface 
grinder  wheel,  the  shear  is  ground  uniformly  for  each  of  the  four  stations 
to  which  the  punch  is  set.  The  high  spots  at  which  the  four  sheared 
surfaces  join  are  clearly  indicated  by  the  four  radial  lines  across  the  face 
of  the  punch. 


FIG.  564.  —  Method  of  grinding  shear  on  face  of  round  punch 


FIG.  565.  —  Die  maker's  files 

THE  FILING  PROCESS 

Returning  now  to  the  actual  work  of  finishing  out  the  interior  of  a  die 
opening,  we  may  give  a  little  consideration  to  the  filing  processes,  hand  and 
machine,  which  are  indispensable  in  the  carrying  out  of  the  work  of  the 
die  maker.  The  needle  files  and  the  die  sinker's  files  on  the  bench  plate 
in  Fig.  565  are  of  the  forms  commonly  required  for  die  work  and  with  the 
exception  of  a  very  few  shapes,  the  two  classes  of  files  are  similar  in  section, 
but  differ  in  respect  to  the  shank  and  therefore  in  the  means  of  holding. 


384 


PUNCHES  AND  DIES 


III 
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LAYING  OUT  AND  MAKING  TEMPLETS  AND  DIES 


385 


386 


PUNCHES  AND  DIES 


The  needle  files  are  made  with  long  slim  shanks  or  round  handles  about 
4  in.  in  length  while  the  other  type,  known  as  die  sinker's  files,  are  provided 
with  the  usual  pointed  tang  which  is  used  commonly  with  a  small  handle 
that  often  is  nothing  more  than  a  disk  or  wafer  shaped  affair  (as  seen  in 
the  half  tone)  which  gives  a  light  finger  grip. 


FIG.  568.  —  Filing  out  a  die  opening 


FIG.  569.  —  Files  used  in  filing  machine 

The  two  classes  of  files  are  shown  in  detail  and  designated  by  name  in 
accordance  with  their  shapes,  in  Figs.  566  and  567. 

The  machine  filing  process  has  eliminated  a  large  share  of  hand  filing 
on  many  classes  of  dies  and  greatly  expedited  the  work  of  the  die  maker. 
With  the  bench  filing  machine  he  can  watch  the  outlines  of  his  work  and 


FIG.  570.  —  Bench  filing  machine  files  (Disston)  Page  387 


388 


PUNCHES  AND   DIES 


with  the  file  mechanically  operated  he  can  work  the  die  along  the  table 
and  remove  the  stock  at  the  necessary  places  with  little  liability  of  over- 
running the  outline.  And,  with  the  table  adjusted  to  the  desired  angle 
for  clearance,  whether  \  degree  or  more,  he  can  feel  assured  that  he  is 
holding  to  close  uniformity  to  this  clearance  throughout  the  process,  and 
that  he  is  not  likely  to  secure  a  bell-mouthed  die  in  the  operation. 


00 


0 


1 


FIG.  571.  —  Nos.  00-0-1-  and  2  cuts  for  machine  files  (exact  size  of  cut) 

A  typical  piece  of  work  on  the  filing  machine  table  is  illustrated  by 
Fig.  568.  A  group  of  files  made  specially  for  such  machines  is  shown  by 
Fig.  569.  The  shapes  of  these  files  with  dimensions  are  given  in  Fig. 
570.  Ordinarily  they  are  made  in  four  cuts,  or  degrees  of  coarseness. 

These  are  designated  as  Cuts  Nos.  1,  2,  3, 
and  4.  The  exact  size  of  the  teeth  for  these 
respective  cuts  is  given  in  the  engraving, 
Fig.  571. 

DIE  MAKER'S  SQUARES 

The  die  maker  has  constant  use  for  squares 
of  various  kinds  in  all  of  his  work  and  particu- 
larly in  filing  nut  blanking  dies  and  openings  of 
similar  character  in  other  tools.  The  sketch, 
Fig.  572,  gives  the  principal  dimensions  of  a 
very  handy  square  which  is  designed  for  fairly 
small  work  but  which  may  be  made  to  propor- 
tions to  suit  any  class  of  work. 
Its  special  feature  is  the  hole  beneath  the  blade,  enabling  one  to  see 
what  sort  of  contact  is  made  between  the  blade  and  the  work  inside  a  hole 
or  slot  in  a  die.  As  the  amount  of  clearance  used  in  different  shops  varies, 
the  blade  is  adjustable.  The  base  is  made  in  two  parts,  so  that  the  sides 
of  the  slot  holding  the  blade  can  be  ground  parallel.  In  this  way,  a  fit  can 
be  made  that  will  be  tight  enough  to  hold  the  blade  in  place.  While  this 
blade  is  put  in  with  a  rivet,  a  tapered  screw  or  some  other  means  can  be 
used  that  will  fasten  the  blade  securely  and  still  be  easily  loosened  when  it 
needs  adjusting. 


FIG.  572.  —  Die  maker's  ad- 
justable square 


LAYING  OUT  AND  MAKING  TEMPLETS  AND  DIES 


389 


A  square  with  this  improvement  of  a  screw  at  the  side  of  the  stock  for 
securing  the  blade  in  fixed  position  is  shown  in  Fig.  573.  The  square  re- 
ferred to  is  at  the  left  of  the  group  of  three  in  this  photograph.  The  one 
in  the  center  is  the  conventional  fixed  blade  tool  and  the  one  at  the  right 
is  a  square  with  blade  secured  by  the  knurled  nut  at  the  front  of  the  stock. 
All  three  squares  are  very  useful  parts  of  the  die  maker's  tool  equipment. 

GKINDING  OUT  DIES 

Reference  has  been  made  to  the  possibility  of  finishing  various  shapes 
of  dies  by  grinding  out  after  hardening,  and  a  few  views  are  here  shown 
where  the  grinding  wheel  is  employed  for  such  operations.  Naturally  an 


FIG.  573.  —  Die  maker's  squares 

internal  process  of  the  kind  mentioned  is  most  readily  performed  with  dies 
having  circular  openings,  as  with  round  blanking  dies,  and  piercing  dies 
of  large  enough  opening  to  admit  the  wheel.  But  there  are  numerous  in- 
stances, also,  where  the  die  opening  terminates  in  a  rounded  end  or  a  round 
corner  or  where  an  arc  is  formed  along  the  main  portion  of  the  contour  all 
of  which  allow  a  wheel  to  be  employed  to  advantage  if  the  size  will  permit 
a  wheel  to  be  used  at  all.  Then,  too,  the  straight  lines  connecting  circular 
portions  sometimes  allow  a  grinding  wheel  to  be  entered  to  finish  these 
•  edges  with  the  work  stationary  just  as  the  circular  parts  are  ground  out  by 
rotating  the  machine  spindle. 

In  Fig.  574,  a  die  is  shown  set  up  on  the  bench  lathe  face  plate  for  the 
finishing  of  the  round  end  of  the  die  opening  by  the  traverse  spindle  grinder. 
The  die  is,  of  course,  located  by  indicating  before  securing  to  the  face  plate 
and  the  work  of  sizing  the  portion  referred  to  is  then  an  easy  process. 


390 


PUNCHES  AND  DIES 


The  spindle  with  the  wheel  is  set  around  to  the  necessary  angle  by  the 
compound  rest  to  provide  for  the  degree  of  clearance  desired  inside  the  die. 
The  operations  illustrated  by  Figs.  575  and  576  consist  of  indicating 
the  die  in  the  chuck  jaws  of  the  internal  grinder  and  then  grinding  out  the 
piercing  opening.  The  chuck  jaws  are  faced  true  with  the  wheel  and  owing 
to  the  shape  of  the  die  there  is  no  difficulty  in  holding  the  work  satisfactorily 


FIG.  574.  —  Finishing  die  opening  with  traverse  spindle  grinder 

in  this  manner.     If  necessary  it  would  be  an  easy  matter  to  secure  the  die 
to  a  face  plate  and  follow  the  same  process  of  indicating  and  grinding. 

While  the  operations  illustrated  are  the  grinding  of  the  circular  piercing 
opening,  the  same  operation  may  be  performed  on  the  circular  enlarge- 
ment at  the  center  of  the  blanking  die  proper.  The  method  of  indicating 
would  be  the  same  and  the  wheel  could  be  applied  in  exactly  the  same  man- 
ner as  for  the  plain  cylindrical  hole. 

OPERATIONS  ON  PUNCHES 

The  machining  and  finishing  of  punches,  consisting  as  it  does  of  the 
working  of  external  surfaces,  is  generally  speaking  a  simpler  problem  than 
the  making  of  dies,  just  as  the  finishing  of  the  outside  surface  of  any  part 
is  usually  more  easily  accomplished  than  are  the  corresponding  operations 
necessary  to  the  completion  of  an  internal  piece  of  work.  Plain  cylin- 


LAYING  OUT  AND  MAKING  TEMPLETS  AND  DIES  391 


FIG.  575.  —  Method  of  indicating  die  before  grinding 


FIG.  576.  —  Grinding  out  the  die 


392 


PUNCHES  AND  DIES 


drical  punches  and  others  of  regular  section  are,  of  course,  readily  machined 
and  there  are  various  other  forms  which,  although  apparently  difficult  to 
produce  when  first  considered,  yet  admit  of  handling  by  the  elementary 
processes  of  the  lathe,  or  the  milling  machine. 

Examine,  for  example,  the  punch  shown  on  the  lathe  carriage  in  Fig. 
577.  This  is  for  cutting  off  flat  stock  to  produce  the  round  end  link  shown 
in  Fig.  578.  It  is  obviously  a  lathe  or  a  milling  machine  undertaking  to 


FIG.  577.  —  Making  a  punch  in  the  lathe 

shape  the  opposite  sides  of  the  punch  to  the  concaved  form  required.  In 
fact  such  punches  are  made  in  both  machines  mentioned,  but  in  the  case 
illustrated  the  lathe  is  being  used  for  the  purpose.  The  metal  which  this 
punch  shears  is  rather  heavy  and  there  is  considerable  clearance  between 
punch  and  die  so  that  the  requirements  as  to  accuracy  of  dimensions  are  not 
exacting,  otherwise  the  punch  blank  could  have  been  secured  in  a  holder 
and  the  latter  mounted  on  the  lathe  face  plate  for  assuring  a  closer  adjust- 
ment in  setting  for  the  two  cuts  to  be  taken  on  the  opposite  sides  of  the 
work. 

In  this  instance  the  punch  is  shown  gripped  in  the  four-jaw  chuck 
and  offset  from  center  the  right  distance  for  the  turning  out  of  the  side  to 
the  necessary  arc  for  rounding  the  cut-off  link  properly.  Upon  completion 
of  the  first  side  the  chuck  jaws  are  set  over  to  throw  the  work  the  same 


LAYING  OUT  AND  MAKING  TEMPLETS  AND  DIES 


393 


distance  the  other  way  from  the  center  for  the  boring  out  of  the  second 
concave  form. 

The  die  is  seen  at  the  front  of  the  carriage.  A  die  of  this  form,  if  solid, 
requires  considerable  time  in  the  working  out  of  the  opening.  If  made  in 
sectional  form  as  in  Fig.  578  the  parts  are  turned  out  without  difficulty, 
the  ends  AA  being  bored  as  readily  as  a  ring,  and  the  side  pieces  BB  turned 
and  let  into  their  places  after  which  the  outside  portions  are  turned  to 
match  the  diameter  of  the  die  as  a  whole. 


END  OF  WORK 


PLAN  OF  PUNCH 


PLAN  OF  DIE 

FIG.  578.  —  Punch  and  die  for  cutting  off  links  with  rounded  ends 

A  milling  machine  operation  on  a  punch  of  crescent  form  is  shown  by 
Fig.  579.  Here  the  work  is  seen  set  up  on  the  face  plate  of  the  dividing 
head  and  the  interior  cut  is  underway.  The  outer  surface  has  already  been 
milled  down  closely  to  the  outline  scribed  on  the  punch  face  and  the  inner 
cut  will  be  similarly  brought  close  to  dimensions  before  the  punch  is  re- 
moved from  the  machine.  The  cutter  is  held  in  the  spindle  of  the  vertical 
milling  attachment  which  is  here  swung  to  horizontal  position,  and  the 
work  is  fed  past  the  cutting  teeth  by  rotation  of  the  dividing  head  crank. 

LARGER  DIE  WORK 

A  method  of  machining  a  large  set  of  dies  is  shown  by  Figs.  580  ard 
581.  These  dies  are  similar  to  certain  sets  illustrated  in  other  sections 
of  this  book.  They  are  of  elliptical  form  and  have  a  long  diameter  of 
about  18  in.  The  parts  being  machined  in  the  lathe  are  of  cast  iron  and 
these  castings  when  finished  are  fitted  with  tool  steel  cutting  rings  which 


394 


PUNCHES  AND  DIES 


FIG.  579.  —  Milling  a  crescent  shaped  punch 


FIG.  580.  —  Making  large  dies 


LAYING  OUT  AND  MAKING  TEMPLETS  AND  DIES 


395 


are  shrunk  or  pressed  into  place  according  to  whether  they  are  fitted  to  the 
male  or  female  die. 

The  point  brought  out  by  the  illustrations  is  the  method  of  locating 
on  the  faceplate  of  the  lathe  by  means  of  a  parallel  along  which  the  work 
may  be  adjusted  for  position  for  the  boring  operations  at  opposite  ends. 
In  Fig.  580  the  die  is  represented  in  the  operation  of  boring  of  the  circular 


FIG.  581.  —  Boring  out  large  die 

portion  at  the  right  of  the  center.  For  boring  out  the  ends  to  larger  radius 
the  work  is  moved  along  the  parallel  and  reclamped  at  the  right  distance 
from  the  center  to  give  the  position  for  sweeping  out  the  metal  at  the  end  of 
the  cored  chamber.  For  the  opposite  end  of  same  radius  the  work  is  simply 
reset  at  the  same  distance  from  the  other  side  of  the  center.  The  turning 
out  of  the  still  larger  curves  at  the  sides  is  accomplished  as  with  the  die 
member  seen  in  Fig.  581,  where  the  curve  is  swept  out  to  join  the  arcs  of 
shorter  radius  already  finished. 

Elliptical  attachments  for  the  lathe  have  been  used  for  such  work  with 
success  but  they  are  not  always  available  when  special  work  comes  along 
that  has  to  be  put  through  the  shop  in  the  least  possible  amount  of  time. 


CHAPTER  XVIII 
LOCATING  HOLES  ACCURATELY  IN  DIE  WORK 

The  problem  of  locating  holes  in  dies  with  the  degree  of  accuracy  de- 
sired is  sometimes  a  difficult  one,  particularly  where  no  special  means  in 
the  way  of  a  vernier  equipped  drilling  machine  or  other  tool  of  similar 
purpose  is  available.  The  small  holes  often  required  in  piercing  dies  and 
in  progressive  piercing  and  blanking  tools  are  generally  more  difficult  of 
location  if  extreme  accuracy  is  essential,  than  where  holes  of  fair  diameter 
are  to  be  bored.  For  the  small  dimensions  of  the  holes  (and  often  of  the 
die  itself)  may  render  the  usual  type  of  button  unavailable  for  the  purpose. 
Owing  to  the  fact  that  the  button  holding  screw  cannot  be  made  smaller 
than  a  certain  minimum  it  may  be  larger  than  the  hole  to  be  bored,  and 
even  though  the  die  is  to  be  bushed  so  that  a  larger  hole  is  permissible,  the 
close  center  distance  between  holes  may  make  it  impracticable  to  button 
up  the  work  in  the  manner  followed  with  similar  problems  where  there  is 
more  space  between  centers.  *_"  '  -  /  - 

Aside  from  the  necessity  for  many  such  holes  in  connection  with  piercing 
dies,  there  are  some  shops  where  it  is  customary  to  outline  all  blanking 
dies  by  means  of  small  holes  drilled  at  the  corners,  and  at  the  ends  of  lugs 
and  projections.  These  holes  then  form  the  limiting  points  to  which  all 
outlines  in  the  die  must  be  carried.  They  must  be  correctly  positioned  or 
the  die  will  be  inaccurate.  They  are  usually  of  necessity  quite  small  in 
diameter  for  often  they  are  used  for  the  additional  purpose  of  leaving  a 
small  fillet  in  the  die  corners  to  produce  a  similarly  small  rounded  corner 
on  the  corresponding  part  of  the  blank.  Where  a  perfectly  square  corner 
on  the  work  is  not  necessary  this  practice  undoubtedly  results  in  a  better 
appearing  blank  and  a  stronger  corner  in  the  die.  Under  certain  con- 
ditions, as  stated  above,  it  may  add  to  the  difficulties  of  making  the  die  in 
the  first  place,  but  under  other  circumstances  where  holes  are  not  too 
closely  spaced  and  where  suitable  toolroom  equipment  is  in  use,  the  prac- 
tice referred  to  may  be  of  real  aid  to  the  die  maker,  who  thus  establishes 
at  the  outset  all  limiting  points  in  the  work  to  which  all  contour  elements 
of  the  die  must  be  held. 

An  illustration  of  a  blank  of  this  kind  is  presented  in  Fig.  582.  At  A 
is  shown  the  blank  with  the  radius  of  each  corner  and  fillet  specified.  The 
layout  of  the  holes  to  be  first  drilled  in  the  die  block  is  given  at  B.  The 

396 


LOCATING  HOLES  ACCURATELY  IN  DIE  WORK 


397 


outline  of  the  die  opening  to  be  worked  out  after  the  holes  have  been  drilled 
is  indicated  by  the  dotted  lines. 

The  centers  of  the  holes  may  be  laid  out  by  vernier  height  gage  as 
shown  in  the  previous  chapter,  with  the  die  block  clamped  to  an  angle 
plate  on  the  surface  plate  and  the  centers  at  the  intersecting  points  of  the 
scribed  lines  can  be  marked  by  a  center  punch  and  then  drilled,  or  indi- 
cated on  the  faceplate  of  the  lathe  and  drilled  in  the  machine.  Or  if 


--  -Face  Plate 


1  1 

"Vic  Rad 
Vio  Rad 

THE  BLANK 

I 

Rad 


ilr 
I- 


_,         -/«  Holes 
LM 


POSITIONS  OF  HOLES 
IN  BLANKING  DIE 

FIG.  582.  —  A  blank  and  the  location 
of  limiting  holes  in  the  die 


FIG.  583.  —  Application  of  the  locating 
button  and  test  indicator 


space  is  sufficient  the  button  method  may  be  employed  as  in  Fig.  583 
and  each  hole  indicated  as  shown  and  bored  to  exact  location  and  size. 
The  buttons  are,  of  course,  set  in  position  on  the  die  by  measuring  across 
with  micrometers  or  other  precision  tools. 

APPLICATION  TO  PROGRESSIVE  DIES 

A  good  illustration  of  the  principles  involved  in  the  making  of  a  pro- 
gressive die  with  several  small  holes  therein  can  be  gathered  by  following 
the  different  stages  in  connection  with  the  tools  for  a  clock  part  shown  in 
Fig.  584. 

From  this  sketch  it  will  be  seen  that  a  tolerance  of  only  0.0005  in. 


398 


PUNCHES  AND  DIES 


either  way  is  allowed  for  the  center  distances  of  all  three  holes.  The  cir- 
cular rack  A  is  rough  blanked  in  the  same  die,  sufficient  stock  being  left  for 
a  finish  shaving  operation  in  another  die. 

The  layout  of  the  first  die  is  given  in  Fig.  585.  The  blank,  which  is 
No.  19  gage  (0.0437  in.)  cold  rolled  steel,  does  not  have  to  be  held  to  close 
limits,  with  the  exception  of  the  circular  rack  part.  As  this  is  finished  in  a 
later  operation,  the  spacing  of  the  three  holes  with  sufficient  accuracy  com- 
prises the  real  problem  in  this  case. 

The  die  opening  A,  Fig.  585,  is  worked  out  to  a  model  and  the  fa-in. 
holes  B,  C  are  bored  part  way  through  the  die  blank,  the  clearance  holes 
being  large  enough  for  the  full  passage  of  slugs. 

Two  pieces  of  drill  rod  fa  in.  in  diameter  by  fa  in.  long  are  next  driven 
into  these  holes,  and  two  f-in.  holes  are  drilled  and  reamed  halfway  into 


FIG.  585 


FIG.  586 
FIGS.  584-586.  —  Locating  small  holes  accurately  in  dies 

the  die  blank  and  the  drill-rod  plugs,  as  at  F.  The  plugs  are  next  removed, 
and  the  die  blank,  with  the  finished  die  opening  A,  is  hardened.  After 
hardening,  this  die  opening  is  honed  and  retouched  to  fit  the  model.  The 
drill-rod  plugs,  together  with  J-in.  dowel  pins  in  holes  F,  are  driven  in,  and 
the  die  blank  is  ground  parallel  on  both  faces.  Also,  the  edges  G  and  H 
are  ground  square,  the  edge  H  being  parallel  to  the  center  line  of  the  three 
holes.  Grinding  the  edges  G  and  H  facilitates  locating  the  button  and 
the  drill  plate  while  the  die  blank  is  resting  on  those  edges  on  the  surface 
plate,  as  will  be  shown  later. 

Next  the  plug  in  the  hole  C  is  drilled  and  tapped  for  the  button  screw, 
and  the  button  is  set  to  the  correct  location  by  the  usual  method,  using 
an  indicator  in  the  height  gage  and  taking  the  necessary  measurements 
from  points  of  the  finished  die  opening.  The  button  thus  secured  is  trued 


LOCATING  HOLES  ACCURATELY  IN  DIE  WORK  399 

up,  and  the  0.2197-in.  hole  is  bored  out  in  the  lathe.  For  the  two  0.051-in. 
diameter  holes  the  following  method  is  employed:  A  piece  of  fk-in.  flat 
cold-rolled  steel  is  drilled  so  that  a  0.051-in.  rod  is  a  good  sliding  fit  in  the 
hole,  after  which  the  cold-rolled  steel  plate  is  cyanided. 

WORK  ON  THE  INSERT 

Fig.  586  shows  the  successive  steps  in  locating  and  drilling  the  two 
0.051-in.  holes  in  the  inserted  drill-rod  plug  in  the  die  blank.  With  a 
0.051-in.  plug  A,  Fig.  586,  in  the  drilled  hole  of  the  cyanided  plate  B,  and 
a  plug  C,  consisting  of  two  diameters  —  namely,  0.2197  in.  and  0.051 
in.  —  concentric  with  each  other  (a  good  fit  in  the  previously  bored  hole 
of  the  die),  locating  the  plug  A  correctly  for  one  of  the  small  holes  is  but  a 
matter  of  measuring  with  micrometers  and  the  height  gage  from  plug  to 
plug,*  testing  with  the  height  gage  as  shown. 

After  the  plug  A  with  the  plate  B  has  been  tapped  into  place,  the  plug 
A  is  removed  and  the  die  blank,  with  the  drill  plate  held  securely  with 
clamps,  is  taken  to  a  drilling  machine.  At  E,  Fig.  586,  is  shown  the 
die  blank  resting  on  parallels  on  the  table  of  the  drilling  machine,  prepara- 
tory to  drilling  the  0.051-in.  hole.  It  might  be  said  that  the  hole  is  first 
spotted  through  the  drill  plate  with  a  0.051-in.  drill,  then  drilled  right 
through  with  a  drill  a  few  thousandths  less  in  diameter  and  finally  reamed 
with  a  0.051-in.  twist  drill,  which  has  the  corners  rounded  so  as  to  produce 
a  smooth  hole.  The  drill  plate  is  next  removed  and  the  remaining  hole 
treated  identically. 

All  three  holes  are  now  taper  reamed  from  the  back  for  clearance; 
both  TVm-  drill-rod  plugs  are  removed  from  the  die  blank  and  hardened, 
after  which  they  are  again  pressed  back  in  their  respective  holes,  the  J-in. 
dowels  lining  them  up  to  positions  they  occupied  while  being  drilled  and 
bored.  A  slight  finishing  cut  is  taken  over  the  die  face  in  the  surface 
grinder,  thus  completing  the  die  blank.  The  punch  holder  plate  for  this 
die  is  drilled  by  the  same  method;  and  the  blanks,  when  they  come  from 
this  punch  and  die,  are  well  within  the  limits  specified.  In  cases  where  one 
of  these  drill  plates  is  to  be  used  frequently,  it  is  a  good  policy  to  make  them 
out  of  hardened  tool  steel;  a  piece  of  ground  tool  steel  stock  does  nicely 
for  this  purpose. 

The  method  just  described  is  a  very  valuable  one  in  shops  where  the 
equipment  is  not  of  the  best,  but  where  the  quality  of  work  turned  out 
is  expected  to  be  first  class. 

THE  PRECISION  LAYOUT 

In  some  factories  the  drawing  office  supplies  the  die  maker  with  a 
complete  layout  of  the  tools  required  so  that  the  centers  of  all  holes  are 
given  in  thousandths  of  an  inch  from  one  starting  point  which  once  located 


400 


PUNCHES  AND   DIES 


forms  the  zero  mark  from  which  every  hole  is  accurately  spaced.  The 
drawing  in  Fig.  587  shows  a  progressive  piercing  and  blanking  die  for  the 
blank  in  Fig.  588  with  all  holes  located  in  reference  to  this  zero  point. 


1st  Position  cf  Stock 


No. 3  Drill  .213 
%"  C-Bore 


PRECISION  LAYOUT 

67  TOOTH  RATCHET  FEED-5  TEETH-STEP  820 
STOCK-.025"X  2H"X  COIL  SPRING  STEEL 


FlG.  5  88 


.025  Spring  Steel 
2  per  Much. 


Mark  Stripper  with  Ratchet 

and  No.  of  Teeth  and  Fit 

with  2  Starting\Stops 


3!       ST-0981 


FIG.  5  87 


B-14 

1 

^"x  IH"  S.q.Hd. 

Set  Screw 

B-13 

2 

^"x  X"   Sq.Hd. 

Set  Screw 

B-12 

4 

5/lG"x  lJ4"Fil.id..J 

B-ll 

2 

•Vl6"x  1%"D.K. 

Dowel 

B-10 

2 

VlC"  x  1"D.R. 

Dowel 

B-9 

2 

5/16"  x  «"F.il.Hd. 

B-3 

I?4"x3"x  WT.S-. 

Punch 

B-7 

%"x  2"D.R. 

Pilot 

i;-0 

.075"x  1%"D.R. 

#-48  Punch 

B-5 

9/32"  x  1H"D.R.. 

Bush 

B-4 

3/16"  x  1%"D.  R. 

Punch 

B-3 

H"k  1H"D.  R. 

Bush 

B-2 

JTx  4"x  3"M.  8.. 

Punch  Plate 

B-l 

ST  1973 

Stock 

A-10 
A-9 

ST-C892 
8  T-  0595 

%,'Guide  Pin 

li>/16     .» 

A  -3 

5/lii"x  //io"Di:R  . 

Bosh 

A-7 

}^"x  23»"D.B. 

Dowel 

A-B 

5/16"  x  2"til.Hd. 

A  -5 

J4"x  7/io"Drill  Rd. 

Bush 

A-4 

%1'x  7/iG"D.rill  Rd 

Bush 

A-3 

J4"x  6"x  4"M.S. 

Stiippcr 

A;2 

l"x  4"x  4H"T.  S. 

Die 

A-l 

I 

STr6981 

Stock 

No 

(Juan 

Material 

Remarks 

FIGS.  587-588 

This  is  a  typical  layout  as  made  by  the  Smith  Premier  Typewriter  Com- 
pany for  use  in  connection  with  the  precision  drilling  machine  made  by 
them  for  use  in  their  tool  room.  The  same  principle  however  can  be 
adapted  for  service  in  tool  rooms  having  a  milling  machine  with  vernier 
scales  attached  for  the  table  and  knee  movements,  although  naturally  the 


LOCATING  HOLES  ACCURATELY  IN  DIE  WORK 


401 


special  drilling  machine  noted  has  certain  advantages  for  this  peculiar 
class  of  work  not  to  be  expected'of  the  general  purpose  tool  room  miller. 
The  precision  drilling  machine  has  a  vertical  spindle  mounted  in  a  slide 
with  power  mechanism  for  feeding  the  drill  through  the  work.  There  is 
a  rigid  drill  support  which 
guides  the  drill  at  the  point 
of  cutting  and  the  work  is 
held  on  a  table  which  closely 
resembles  in  design  and  opera- 
tion the  table  of  a  milling  ma- 
chine, as  it  is  fitted  to  a  saddle 
on  a  knee  of  the  miller  type  and 
has  therefore  all  of  the  move- 
ments of  the  miller  table.  The 
machine  is  built  with  extreme 
accuracy  and  its  performances 
in  the  correct  locating  of  holes 
in  dies  and  similar  tools  are  re- 
markable not  only  because  of 
the  degree  of  accuracy  obtained 
in  the  work  but  also  because  of 
the  rapidity  with  which  it  ac- 
complishes its  operations.  The 
table  and  saddle  are  equipped 
with  vernier  scales.  The  drill 
support  is  equipped  with  a  set 
of  hardened  and  lapped  bush- 
ings varying  in  diameter  of 
hole  from  No.  54  drill  size  to 
f  in.  Holes  as  large  as  2  in.  can 
be  bored  by  means  of  an  eccen- 
tric boring  tool.  A  general  view 
of  this  interesting  precision  tool 
is  presented  in  Fig.  589. 


FIG.  589.  —  Precision  drilling  machine 


How  THE  PRECISION  LAYOUTS  ARE  USED 

The  toolmaker  in  charge  of  this  machine  is  assisted  considerably  on  the 
job  by  the  provision  of  the  precision  layout  by  the  drafting  room.  The 
layout  is  made  at  the  same  time  the  tool  is  drawn  up  and  gives,  for  the  sake 
of  clearness,  merely  the  information  needed  to  perform  the  precision  drill- 
ing. Samples  of  these  layouts  are  shown  in  Figs.  587,  590,  and  591. 
The  toolmaker  clamps  the  work  to  the  table  and  brings  the  work  under 
the  spindle  so  that  the  latter  is  directly  over  the  zero  point  as  indicated  on 


402 


PUNCHES  AND   DIES 


the  layout.  The  zero  point  may  be  scaled  from  the  edge  of  the  work,  as 
is  necessary  in  Figs.  587  and  590,  or  it  may  be  at  the  corner  of  the  block. 
When  the  drill  spindle  is  over  the  zero  point,  as  shown  by  an  indicator  in 
the  chuck,  the  scales  on  the  table  and  spindle  are  set  very  carefully  at  zero. 
The  holes  on  the  layout  are  all  located  in  thousandths  from  the  zero  point 
in  two  directions,  thus  enabling  the  toolmaker  to  complete  the  drilling 
without  resetting  the  scales.  The  rest  of  the  operation  is  simple,  the  tool- 
maker  carefully  moving  the  table  until  the  scale  readings  correspond  to  the 
coordinates  as  given  on  the  layout  and  then  selecting  the  proper  bushings, 

drill,  and  reamer  to  com- 
plete the  hole.  Care  is 
taken  to  have  the  work 
close  to  the  drill-support 
slide  so  that  the  point  of 
the  drill  is  steadied  as  it 
enters  the  work.  To 
change  the  drills  the  drill 
is  raised  from  the  bushing, 
the  slide  undamped  and 
pushed  back  in  the  frame 
and  the  drill  taken  out. 

The  use  of  the  scales 
permits  the  exact  location 
of  the  work  in  relation  to 
the  drill  spindle  regard- 


•fclbore.—; 

f^texk.  /  /  /  /   T^T^-M. 

KU  /  /  /   / 

/  __      »          I    I 

C^-'ti  I 

L     '-^?-L'.i 


-JC 


h-. 


-y&s-".... 
«*^j 


-i 


Ratchet,  ?9Teeth 
Feed,  2  Teeth 
Step,  0.756" 


FIG.  590.  —  Layout  for  blanking  die  precision 


less   of   any   backlash   or 


wear  in  the  lead  screws.  The  drill  support,  which  insures  the  drilling 
of  the  holes  in  the  exact  spot  required,  is  used  only  until  the  drill  is 
started  in  the  work.  Then  it  is  moved  back  and  the  hole  drilled.  This 
is  done  to  reduce  the  wear  in  the  bushings.  The  reaming  is  done  through 
the  bushings. 

The  precision  drill  has  been  used  effectively  in  the  laying  out  of  dies 
and  in  the  removing  of  stock  from  die  blocks.  It  is  equally  effective  in 
locating  bushing  holes  in  drill  jigs.  It  has  also  been  of  great  assistance  in 
the  making  up  of  models  prior  to  the  starting  of  regular  production. 

In  Fig.  590  is  shown  a  good  example  of  the  layout  for  a  blanking  die  to 
be  used  in  a  press  with  automatic  feed.  The  exact  location  for  the  holes 
for  piercing  punches  and  leaders  in  the  die  block  is  thus  quickly  provided. 
The  layout  in  Fig.  590  is  shown  with  the  axes  at  an  angle  of  10  degrees 
with  the  side  of  the  die  block.  This  does  not  lengthen  the  operation  on 
the  precision  drill  as  the  stock  can  be  clamped  on  a  swivel  table  and  turned 
to  the  required  angle  quickly.  The  work  of  preparing  the  layout,  however, 
is  considerably  decreased  as  the  axes  are  parallel  to  the  center  line  of  the 


LOCATING  HOLES  ACCURATELY  IN  DIE  WORK 


403 


part  drawing  and  therefore  the  calculation  of  the  coordinates  is  simplified 
by  merely  having  the  block  turned  at  the  required  angle. 

In  Fig.  591  is  shown  an  example  of  a  die  block  with  a  large  part  of  the 
stock  removed  on  the  precision  drill.  This  die  is  subjected  to  severe 
service  and  requires  frequent  replacement.  Consequently  it  is  considered 
economical  to  provide  a 
very  complete  precision 
layout  giving  ordinates 
and  drill  sizes  so  that  the 
finishing  time  for  the  die 
would  be  materially  re- 
duced. The  irregularity 
of  the  form  of  this  die 
would  make  a  difficult 
task  of  laying  out  for 
drilling  by  the  die  maker 
in  a  sensitive  drilling  ma- 
chine. The  irregularity  of 
form  would  also  increase 
the  probability  of  error 
and  the  consequent  spoil- 
ing of  the  die  by  the  die- 
maker.  The  precision 
drill,  however,  takes  care 
of  this  job  in  a  very  simple 
fashion,  and  the  work 
comes  to  the  diemaker  in 
a  manner  that  requires  the 
minimumof  stockremoval.  FlG'  591'  ~  Precision  u*uut  for  blanking  *• 

The  use  of  the  precision  drill  for  Fig.  591  does  away  with  the  necessity 
for  making  accurate  templets  for  laying  out  the  curved  edges  of  the  die. 

THE  USE  OF  MASTER  PLATES 

The  master  plate  is  a  device  well  known  to  tool  makers  engaged  on  high 
class  work.  It  has  numerous  applications  in  various  branches  of  tool 
work  but  is  less  frequently  employed  in  connection  with  the  making  of 
dies  and  punches  than  with  certain  other  lines  of  precision  work,  although 
there  is  no  tool  room  branch  where  it  can  be  used  more  effectively  than  in 
the  construction  of  press  tools. 

There  is  perhaps  a  certain  amount  of  misunderstanding  in  regard  to  the 
making  of  such  plates  that  tends  to  prevent  the  extension  of  their  uses  to 
the  full  in  connection  with  die  construction  as  well  as  in  some  other  direc- 
tions. It  has  been  found  a  more  or  less  common  belief  in  some  classes  of 


Stamp  H.  T  ?m  Serial  Number  as 
ordered  and  grade  of  Steel 


K- 1671--- 

— -1.800— - 
--  1.944"--- 
k ?.0dd--— 


!! 


V+-------Z9/0------ 


** —375- 

—  -3224-— 


I  k--.  — - 

I*....  ----- jg7#»- , 

FIG.  591.  —  Precision 


_>QJQ8_ 
"~~~*mm 


404  PUNCHES  AND   DIES 

shops  that  the  master  plate  is  specifically  a  watch  tool  maker's  device  and 
that  it  is  limited  by  first  cost  and  unnecessary  refinement  to  the  needs  of 
the  watch  factory  tool  room  and  similar  departments  in  other  shops  doing 
practically  the  same  kind  of  work. 

This  belief,  while  a  commendation  of  the  superior  qualities  of  the 
master  plate,  is  unfortunate  in  so  far  as  it  may  have  delayed  the  adoption 
of  this  most  convenient  device  in  different  tool  rooms  and  for  various  grades 
of  die  work.  The  master  plate  is  truly  a  tool  of  precision,  assuming  it  is 
made  with  the  degree  of  skill  and  care  which  it  merits;  but  it  has  its  legiti- 
mate uses  in  other  places  as  well  as  in  such  tool  rooms  as  turn  out  only  the 
highest  grade  of  precision  work.  And  if  toolmakers  but  stopped  to  realize 
that  the  purpose  of  the  master  plate  is  to  make  possible  exact  duplication 
of  its  own  qualities  of  accuracy,  whether  that  accuracy  is  of  the  highest 
or  of  only  moderate  degree,  they  would  see  many  opportunities  to  employ 
it  to  advantage  where  now  they  only  too  frequently  leave  it  entirely  out  of 
consideration  so  far  as  the  greater  part  of  their  work  is  concerned.  This  is 
true  to  an  even  greater  extent  with  diemaking  than  in  general  tool  room 
practice. 

Now  a  jig  is  a  device  for  duplicating  within  the  running  limits  of  drills 
and  reamers,  the  center  distances  established  by  its  own  guide  bushings. 
If  these  distances  are  accurately  determined  in  the  construction  of  the  jig, 
the  parts  that  are  drilled  therein  will  be  as  close  duplicates  in  respect  to 
hole  locations  as  the  operation  of  the  drills  will  permit.  But  if  we  are  seek- 
ing for  a  perfectly  true  job  of  boring  with  holes  as  straight  and  round  as 
possible,  and  if  moreover  we  wish  to  secure  the  closest  accuracy  in  the  rela- 
tive locations  of  two  or  more  such  holes,  we  will  naturally  resort  to  some 
form  of  face  plate  process  where  the  work  can  be  swung  as  in  a  lathe  and 
where  after  the  centers  of  the  holes  have  been  indicated  with  a  test  indi- 
cator the  work  can  be  drilled  and  then  completed  by  rotating  it  on  its 
own  axis  while  a  boring  tool  is  applied  until  the  hole  is  finished  to  the 
desired  diameter. 

The  master  plate  is  essentially  a  face  plate  appliance.  It  enables  us 
to  mount  our  work  on  the  face  plate  and  secure  for  each  and  every  hole 
bored  out  the  exact  degree  of  precision  in  location  that  is  represented  by 
the  master  itself.  A  center  distance  established  in  the  master  plate  is 
reproduced  exactly  in  the  work  and  if  a  duplicate  job  arises  at  any  time 
it  is  bored  out  with  the  same  degree  of  exactness  as  was  obtained  for 
former  pieces. 

In  its  application  to  press  tools,  it  enables  the  die  maker  to  bore  punch 
plates  and  dies  as  precise  duplicates  of  each  other  with  the  assurance  that 
the  center  distances  thus  obtained  will  bring  the  tools  into  positive  aline- 
ment  when  assembled.  The  replacement  of  either  punch  plate  or  die,  or 
both,  at  any  time  is  readily  accomplished  with  the  aid  of  the  master  plate 


LOCATING   HOLES  ACCURATELY  IN   DIE  WORK 


405 


and  there  will  be  no  question  as  to  the  preservation  of  the  original  center 
distances  in  the  newly  made  parts. 

Whatever  the  qualities  of  the  master  plate  as  to  accuracy,  these  are 
transferred  to  the  work.  If  a  set  of  dies  is  required  of  unusual  degree  of 
accuracy,  the  master  plate  will  be  found  a  most  effective  agent  in  the  carry- 
ing out  of  their  construction.  If  on  the  other  hand  there  is  no  demand  for 
precise  location  of  hole  centers,  but  replacement  of  the  tools  is  a  deciding 
factor,  the  master  plate  will  prove  fully  as  effective  as  in  the  other  case. 

Thus  far  we  have  considered  the  master  plate  as  of  service  in  the  lo- 
cating and  boring  of  holes  only.  It  is  equally  valuable  as  an  aid  to  the 
correct  working  out  of  various  regular  and  irregular  die  openings  and  punch 
forms  on  the  lathe  and  in  the  milling  machine. 


ILLUSTRATION  OF  A  MASTER  PLATE 

As  an  illustration  of  a  simple  master  plate  and  its  application  to  a 
piece  of  die  making  let  us  refer  to  Figs.  592,  593,  and  594.  The  master  plate 
will  be  seen  to  be  a  plain  block  of  steel  in  which  a  series  of  holes  are  accu- 


-Die 

V 

d5  4 

/, 

CL< 

0-3 

B^ 

0*3' 
C 

Q? 

PLAN 

FIG 

OF  DIE 

.594 

PLAN  OF  MASTER  .PLATE 
FIG.  59  3 

FIGS.  592-594.  —  The  use  of  the  master  plate 

0 

rately  bored  to  suit  certain  center  distances  required  in  the  die.  In  use  the 
master  plate  is  placed  on  the  bench  lathe  face  plate  as  in  Fig.  592  where 
it  fits  snugly  over  a  hardened  and  ground  center  plug  A  placed  in  the 
taper  hole  in  the  lathe  spindle.  The  master  plate  B  may  be  secured  by 
light  straps  and  screws  as  indicated  or  by  other  clamping  means,  but  it  is 
obvious  that  it  must  seat  squarely  against  the  perfectly  true  face  plate  and 
be  held  there  without  being  sprung  or  deflected. 

The  work,  the  die  C,  is  secured  by  screws  and  dowels  or  if  quite  small  may 
be  soldered  to  the  face  of  the  master  plate.  With  hole  No.  1  of  the  master 
plate  located  over  the  center  plug  A,  the  work  is  in  position  for  the  boring 


406 


PUNCHES  AND  DIES 


of  the  hole  1'  in  the  die.  When  shifted  to  hole  2  the  plate  brings  the  die 
block  into  position  for  boring  hole  2'  and  so  on  until  the  work  is  completed. 

In  the  illustration,  the  die  has  three  holes  (I/,  2',  3')  for  piercing  and 
there  are  three  locations  (4,  5,  and  6)  for  setting  the  die  for  the  boring  out 
of  the  enlarged  circles  4',  5',  and  6',  for  the  blanking  opening.  These 
larger  holes  are  bored  with  the  same  accuracy  and  convenience  as  the  small 
piercing  holes,  and  after  they  are  completed,  the  plate  and  work  may  be 
transferred  directly  to  a  miller  for  finishing  out  the  die  opening,  to  the  full 
lines  of  the  sketch. 

The  punch  plate  may  be  handled  on  the  same  master  plate  for  the 
boring  of  the  holes  for  the  piercing  punches  and  the  blanking  punch  can  be 


FIG.  595.  —  Master  plates  for  die  work 

milled  up  to  form  by  mounting  the  master  on  the  dividing  head  face  plate 
and  rotating  it  to  swing  the  work  past  the  milling  cutter  for  the  rounding 
of  the  three  lobe  ends.  Held  in  the  same  place  with  the  work  revolved  to 
horizontal  or  vertical  position  the  straight  surfaces  of  the  punch  can  be 
milled  to  desired  dimensions. 

A  blanking  die  with  most  irregular  opening  can  usually  be  worked  out 
from  a  master  plate  without  difficulty  by  providing  a  locating  hole  in  the 
plate  for  each  arc  and  curve  in  the  die  opening. 

With  a  master  plate  once  made,  a  complete  set  of  dies,  piercing,  blank- 
ing, shaving,  etc.,  can  all  be  made  to  uniform  centers  for  accuracy  of  spacing 
by  handling  each  in  turn  on  the  same  master. 

Some  master  plates  for  such  operations  are  illustrated  by  Fig.  595. 
The  dies  for  which  they  are  made  are  used  continuously  and  frequent  re- 


LOCATING  HOLES  ACCURATELY  IN  DIE  WORK  407 

placement  is  necessary.  The  plates  give  all  the  center  locations  for  the 
piercing  holes  and  for  the  various  curves  and  arcs  in  the  blanking  die 
contour. 

The  holes  in  master  plates  themselves  are  located  originally  by  the 
most  accurate  methods  that  the  tool  maker  can  bring  to  bear  upon  the 
work.  The  button  method  is  probably  the  most  commonly  adopted  and 
if  properly  followed  it  will  produce  results  well  within  the  limits  of  any  re- 
quirements likely  to  be  demanded  of  any  plate  in  usual  high-grade  service. 
An  unusual  degree  of  care  is  necessary  in  indicating  the  buttons  and  in 
boring  the  individual  holes  in  the  master  plate.  They  are  generally  drilled 
close  to  boring  size,  bored  to  leave  a  slight  scraping  reamer  cut  and  then 
lapped  by  hand  to  perfect  fit  for  a  plug  gage.  It  will  be  understood  that 
the  plate  itself  must  be  as  nearly  a  plane  surface  as  possible  before  it  is  put 
on  the  face  plate.  It  is  usually  the  case  that  the  tool  steel  plate  is  ground 
and  lapped  on  the  faces  before  boring  operations  are  started. 


CHAPTER  XIX 
MAKING  A  SET   OF   SHAVING  DIES 

The  illustrations  in  this  chapter  represent  the  important  steps  in  the 
construction  of  a  set  of  shaving  dies  ior  a  toothed  blank  T9g-  in.  in  diam- 
eter by  0.050  in.  thick.  The  blank  is  made  from  half  hard  steel  and 
has  nine  Jteeth  0.0887  in.  deep.  The  amount  left  in  blanking  for  finishing 
in  the  shaving  dies  is  0.003  on  a  side  or  a  total  allowance  of  0.006  in. 


FIG.  596.  —  The  shaving  tools 

The  dies  are  of  the  pillar  type  and  are  shown  in  Figs.  596  and  597. 
All  parts  are  seen  in  the  group  photograph,  Fig.  598,  including  even  such 
details  as  dowels  and  screws.  The  die  proper  is  3  in.  square  by  }f  in.  thick. 
The  die  opening  is  made  straight  down  without  clearance  for  a  depth  of  \ 
in.,  below  which  it  is  tapered  out  for  work  clearance  at  an  angle  of  1  degree 
on  a  side.  The  die  can  thus  be  ground  down  to  a  depth  of  \  in.  before  its 
size  becomes  affected  by  the  clearance  angle. 

408 


MAKING  A  SET  OF  SHAVING  DIES 


409 


FIG.  597.  —  Punch  head  removed  from  die 


, 


FIG.  598.  —  Punch  and  die  parts 


410 


PUNCHES  AND  DIES 


WORKING  OUT  THE  DIE  OPENING 

There  are  different  ways  of  getting  out  the  stock  from  a  die  opening 
such  as  is  required  here.  After  the  hole  is  drilled  at  the  center  to  remove  as 
much  material  as  later  operations  will  justify,  the  area  between  the  teeth 
may  be  drilled  out  by  two  or  three  different  sized  drills  to  leave  but  a  narrow 
wall  between  drill  holes  and  a  close  margin  between  holes  and  die  contour. 
Or,  if  the  die  opening  roughed  out  is  sufficiently  large  in  diameter,  a  slot- 
ing  tool  may  be  applied  to  the  work  with  the  die  indexed  in  the  dividing 
head  of  the  miller  and  the  rough  form  of  the  teeth  outlined  by  the  shape  of 
the  slotting  cutter.  In  any  event  enough  stock  must  be  left  to  assure  the 
toothed  contour  being  finished  to  exact  requirements,  and  with  a  small 


FIG.  599.  —  The  die  on  the  bench  filing  machine 

toothed  die  like  this  the  hand  file  and  bench  filing  machine  are  relied  upon 
to  a  large  extent  to  assist  in  getting  the  tooth  form  roughed  down  and  then 
with  a  combination  of  file  and  broach  the  opening  is  finished. 

The  die  is  shown  on  the  filing  machine  in  Fig.  599.  The  half  tone,  Fig. 
600,  shows  the  broaches  used  in  working  the  die  to  shape.  There  are  two 
of  these  broaches,  both  shown  to  the  right  of  the  die.  The  punch,  un- 
finished, is  seen  at  the  left-hand  side  with  the  roughed  out  nest  in  front. 
The  formed  milling  cutters  at  the  right  are  the  ones  used  for  milling  the 
broach  teeth.  • 

The  sizes  of  the  broaches  differ  but  a  few  thousandths  for  only  a  slight 
amount  of  stock  is  removed  by  each  broach.  Even  this  is  taken  out  piece 
meal;  that  is  the  broach  is  forced  into  the  die  opening  say  cV  in.  deep,  then 
removed  and  the  filing  machine  resorted  to  to  work  out  the  depth  of  the  die 
toward  the  minute  shoulder  left  by  the  cutting  end  of  the  broach.  Then 
the  broach  is  forced  in  again,  this  time  another  sixty-fourth  and  the  filing 


MAKING  A  SET  OF  SHAVING  DIES 


411 


process  repeated.  After  the  first  broach  has  been  passed  through  the  die  by 
repeated  stages,  aided  by  the  working  out  of  the  superfluous  metal  by  the 
file,  the  second  broach,  a  couple  of  thousandths  larger,  is  started  through  in 
similar  fashion.  The  operation  of  forcing  the  broach  into  the  die  under  a 


FIG.  600.  —  The  punch,  the  die,  the  broaches  and  lap 

hand  screw  press  is  represented  by  Fig.  601.     For  the  purpose  the  broach 
is  mounted  in  a  punch  head  as  seen  here,  and  the  die  is  placed  upon  the 


FIG.  601.  —  Method  of  broaching  out  the  die 

base  of  a  pillar  set.  The  tools  are  thus  properly  alined  and  the  passing 
through  of  the  broach  is  merely  a  case  of  alternating  between  the  operations 
of-  forcing  the  broach  in  the  slight  distance  referred  to  at  each  step  and 
filing  out  to  correspond  to  the  advance  of  the  broaching  process. 


412 


PUNCHES  AND   DIES 


The  straight  shank  tool  at  the  side  of  the  broaches  in  Fig.  601  is  a  lap 
which  is  used  at  a  later  stage  in  the  finishing  of  the  die.  That  is,  after  the 
die  has  been  sized  by  means  of  the  broaches  and  filed  for  the  slight  clear- 
ance below  the  straight  portion  which  is  j  in.  deep,  the  die  is  drilled  and 
tapped  in  the  four  corners  for  four  f'V-m.  fillister  head  screws  for  holding 
it  to  the  die  base  and  also  drilled  for  two  fVin.  dowels;  it  is  further  drilled 
for  the  screws  and  dowels  for  holding  the  7nest  and  then  it  is  hardened  and 
is  ready  for  lapping  as  in  Fig.  602. 

The  lapping  is  done  under  a  sensitive  drill  spindle,  with  the  lap  held  in 
the  drill  chuck  as  illustrated.  Fine  emery  and  oil  being  applied  to  the  teeth 
milled  along  the  lap  surface,  the  spindle,  while  standing  without  rotation, 


FIG.  602.  —  Lapping  the  die  opening 

is  moved  up  and  down  by  the  operating  lever  to  lap  out  the  entire  toothed 
opening  in  the  die  and  bring  it  dead  to  size  with  all  points  in  the  working 
opening  perfectly  smooth  and  the  working  depth  of  the  die  perfectly  straight. 

OPERATIONS  ON  THE  PUNCH 

The  punch  is  turned  up  in  the  bench  lathe  from  a  length  of  tool  steel. 
It  is  left  with  a  large  body  which  is  swept  out  in  a  liberal  curve  to  the  work- 
ing diameter  of  the  punch  which  is  left  straight  for  a  length  of  1  in.  The 
diameter  of  the  body  is  about  1J  in.  and  back  of  the  enlarged  portion  is  a 
hub  or  extension  which  is  f  in.  diameter.  This  hub  and  the  body  or  en- 
larged shoulder  are  left  a  little  over  size  but  are  afterward  finished  to  fit 
closely  in  recessed  seats  bored  out  in  the  face  of  the  punch  holder  or  head 


MAKING  A  SET  OF  SHAVING  DIES 


413 


as  shown  in  the  detail  engraving,  Fig.  598.  The  outer  end  of  the  punch, 
that  is,  the  working  end,  is  left  \  in.  long  (Fig.  600)  and  is  turned  down  to  a 
size  equal  to  the  diameter  of  the  roots  of  the  teeth  so  that  it  may  serve  as  a 
pilot  in  a  later  operation  where  it  is  sized  by  being  passed  into  the  die. 

The  punch  teeth  are  then  milled  as  in  Fig.  603,  with  the  work  held  on 
the  dividing  head  centers  of  the  milling  machine.  The  formed  gear  cutters 
for  this  operation  are  seen  at  the  extreme  right  in  Fig.  600.  The  teeth  are 
cut  with  great  care  to  produce  smooth  results  and  accuracy  of  size  and  tooth 
forms.  The  punch  is  then  secured  in  a  holder  and. sheared  into^the  die 


FIG.  603.  —  Milling  the  punch 

with  the  projecting  pilot  acting  as  a  guide.  The  tools  are  set  up  for  this 
operation  as  in  Fig.  604  which  illustrates  the  method  of  clamping  the  die  on 
its  base  after  the  punch  head  has  been  slid  down  to  enter  the  punch  pilot 
into  the  die  opening.  With  the  tools  thus  arranged,  they  are  transferred 
to  the  hand-screw  press  and  the  punch  sheared  in  as  explained. 

The  pilot  of  the  punch  is  now  cut  off  by  setting  up  the  punch  in  the 
bench  lathe  and  the  holes  are  drilled  in  its  flange  or  shoulder  for  two 
fillister  head  screws  and  two  dowels.  The  screw  holes  are  tapped  and  the 
punch  is  then  hardened.  After  this  it  is  placed  in  the  bench  lathe  for  the 
grinding  of  the  shoulder  and  shank.  This  shank  or  hub  when  first  turned  is 
left  a  few  thousandths  over  size  and  to  finish  it  to  dimensions  the  punch  is 
placed  in  a  bushing  in  the  chuck  which  is  bored  out  to  receive  the  cutting 
end  of  the  punch.  While  held  in  the  bushing  in  this  manner,  the  punch  is 
tested  for  running  truth  of  the  hub  by  an  indicator  placed  as  in  Fig.  605  and 


414 


PUNCHES  AND  DIES 


FIG.  604.  —  Clamping  the  die  in  line  with  the  punch  for  drilling  holes  in  base 


FIG.  605.  —  Indicating  the  punch  in  the  bench  lathe 


MAKING  A  SET  OF  SHAVING  DIES 


415 


FIG.  606.  —  Grinding  the  punch  shank 


FIG.  607.  —  Drilling  the  punch  holder  for  screws  and  dowels 


416  PUNCHES  AND  DIES 

then  ground  to  diameter  by  a  wheel  on  the  traverse  spindle  grinder,  Fig. 
606.  The  punch  can  now  be  seated  in  its  holder  or  head  as  in  Fig.  607 
and  used  as  a  jig  for  the  drilling  of  the  holder  for  the  screw  holes  and  the 
holes  for  the  dowel  pins. 

Up  to  this  point  the  die  has  not  been  secured  to  its  base  or  shoe.  The 
operation  of  locating  it  in  line  with  the  punch  for  the  drilling  of  the  screw 
and  dowel  holes  in  the  base  is  accomplished  as  shown  again  by  Fig.  604. 
The  punch  head  is  placed  over  the  guide  posts  or  pillars  in  the  die  base  and 
the  punch  entered  into  the  loose  die  proper  to  aline  it  properly  with  the 
punch.  The  clamps  are  applied  as  shown  to  hold  the  die  temporarily  for  the 
drilling  operation  and  the  punch  head  slipped  up  and  off  the  guide  pins.  This 
leaves  the  die  clear  for  the  drilling  of  the  four  screw  holes  and  two  dowel 
pin  holes  in  the  base.  Following  the  drilling,  the  clamps  are  removed,  the 
screws  and  dowels  are  placed  in  position  and  the  die  is  thus  fixed  in 
position  on  its  base. 


FIG.  608.  —  The  nest  and  the  hand  tool 

MAKING  THE  NEST 

The  nest  is  originally  a  round  disk  of  steel  faced  down  to  \  in.  thick  and 
drilled  through  the  center  to  a  size  suitable  for  filing  and  broaching  out  to 
the  shape  and  dimensions  of  the  toothed  blank  which  it  will  be  required  to 
hold  on  the  die  when  in  service.  A  hand  broach  is  used  on  this  thin  nest  in 
addition  to  the  regular  broaches  already  described.  This  broach  is  shown 
at  the  side  of  the  stripper  blank  in  Fig.  608.  It  is  used  in  conjunction  with 
the  filing  process  and  in  connection  with  the  blanking  punch  which  is  made 
use  of  as  in  Fig.  609  for  sizing  the  nest  opening.  The  nest  is  in  fact  set  up 
in  the  regular  blanking  dies  for  the  toothed  wheel  which  it  is  designed  to 
hold,  and  the  blanking  punch  is  applied  as  a  broach  to  assist  in  the  work- 
ing of  the  opening  to  desired  size  and  form.  With  the  punch  entered 
slightly,  say  to  ^  in.  depth,  a  guide  mark  is  formed  in  the  nest  for  enabling 
the  opening  to  be  scraped  and  worked  out  by  means  of  the  file  and  by  the 
hand  tool  in  Fig.  608. 


MAKING  A  SET  OF  SHAVING  DIES 


417 


After  the  nest  opening  is  sized  properly,  the  bottom  side  is  recessed  and 
the  top  is  countersunk  or  chamfered  to  leave  a  beveled  surface  for  easy 
placing  of  the  work  in  the  nest.  The  clearance  underside  is  cut  in  suf- 
ficiently to  leave  an  actual  full  size  nesting  opening  about  two-thirds  as 
deep  as  the  thickness  of  the  stock.  The  recessed  portion  at  the  bottom 
forms  a  clearance  space  for  chips. 

When  the  nest  opening  has  been  completed,  the  sides  of  the  disk  are 
milled  away  to  leave  a  form  similar  to  that  shown  in  Fig.  597  and  the  holes 
are  drilled  for  screws  and  dowel  pins.  This  is  done  in  alinement  with  the 
die  holes  by  using  the  die  as  a  jig. 


FIG.  609.  —  Broaching  out  the  nest 

FINISHING  DOWEL  PINS 

A  word  may  be  added  here  in  regard  to  the  finishing  of  the  various  dowel 
pins  used  in  these  tools.  The  practice  in  the  shop  making  these  dies  is  to 
take  a  length  of  steel  slightly  larger  than  the  required  size  of  dowel  and  long 
enough  for  two  pins  to  be  made  from  one  piece.  The  stock  is  turned  on 
centers  to  say  0.008  in.  above  size  and  then  necked  in  the  middle  to  a  depth 
of  1*5  in.,  then  it  is  hardened.  After  this  it  is  placed  on  dead  centers  in 
the  grinding  machine  as  shown  by  Fig.  610  and  the  diameter  ground  to 
size.  The  work  is  ground  from  one  end  to  the  clearance  cut  at  the  middle 
and  then  reversed  on  centers  and  ground  from  the  other  end.  Following 


418 


PUNCHES  AND   DIES 


FIG.  610.  — •  Grinding  dowel  pins 


FIG.  611.  —  A  set  of  reamers 


MAKING  A  SET  OF  SHAVING  DIES  419 

the  sizing  with  the  wheel,  the  pins  are  separated  by  breaking  them  apart 
at  the  necked  dividing  line. 

These  dowel  pins  are  ground  perfectly  straight  from  end  to  end  and  it  is 
therefore  necessary  that  the  holes  in  die  parts  be  reamed  out  true  and 
straight.  A  convenient  set  of  reamers  for  the  purpose  is  shown  in  Fig.  611. 
These  are  of  all  standard  sizes  required  for  general  die  construction.  They 
are  of  the  rose  type  to  cut  near  the  end  only  and  are  used  after  the  hole 
is  spotted  and  drilled  through  with  a  slightly  smaller  drill,  to  remove  a  very 
small  amount  of  metal  and  leave  the  hole  a  proper  fit  for  the  pins  which 
are  ground  closely  to  standard  dimensions. 


CHAPTER  XX 


SOME  HARDENING  PRINCIPLES   APPLIED   TO   DIES 

After  every  effort  has  been  expended  by  the  die  maker  in  the  production 
of  an  accurate  set  of  dies,  his  labor  may  all  prove  wasted  because  of  im- 
proper treatment  of  the  work  in  the  hardening  process.  There  is  probably 
less  definite  information  available  upon  this  general  subject  of  hardening, 
than  on  any  other  branch  of  the  work.  There  are  also  more  cases  of  die 
failure  traceable  to  improper  hardening  than  to  any  other  cause. 

A  well-known  authority  on  this  subject,  Edward  Dean,  has  set  down 
certain  principles  in  connection  with  the  finishing  and  hardening  of  high 
carbon  steel  dies  that  should  prove  of  benefit  to  every  one  engaged  in  this 
line  of  work.  The  conclusions  drawn  have  been  based  upon  twenty  years 
of  research  work  in  this  direction,  during  which  time  a  large  number  of 

observations  were  made  enabling  the  investi- 
gator to  form  certain  definite  opinions  as  to  the 
action  of  dies  in  the  hardening  process  and  con- 
clusions as  to  the  reasons  for  various  failures 
when  certain  tools  were  placed  in  service. 

All  of  the  work  referred  to  here  was  done  on 
commercial  die  steels  from  96  to  110  point 
carbon.  All  dies  referred  to  were  heated  for 
hardening  in  a  gas  fired  furnace  and  quenched 
in  clear  water  at  about  85°  F. 

As  this  authority  points  out,  we  are  apt  to 
think  that  a  piece  of  tool  steel  hardens  all 
through.  It  is  of  course  true  that  a  piece 
of  hardened  high  carbon  tool  steel  is  harder 
throughout  after  hardening  than  when  it  was  soft.  It  is  equally  true  that 
such  a  piece  of  steel  having  a  section  thicker  than  say  J  in.  has  several  dif- 
ferent degrees  of  hardness.  In  a  manner  it  resembles  a  piece  of  hardened 
carbonized  soft  steel  in  that  it  has  a  very  hard  shell  and  gradually  grows 
softer  as  the  core  is  approached,  although  the  differences  in  hardness  be- 
tween the  various  layers  are  much  less  than  in  the  case  of  the  hardened 
carbonized  low  carbon  steel. 

As  an  illustration  it  is  pointed  out  that  if  a  piece  of  high  carbon  tool 
steel,  say  f  in.  thick,  ?  in.  wide  and  2  in.  long,  is  hardened,  it  will  be  found 
to  have  a  soft  core  surrounded  by  a  harder  shell  as  indicated  by  Fig.  612. 

420 


FIGS.  612-613.  —  Section  of 
specimens  of  hardened  die 
steel  showing  layers  of 
different  hardness 


SOME  HARDENING  PRINCIPLES  APPLIED  TO  DIES  421 

The  difference  in  hardness  between  the  two  areas  is  some  3  to  5  points 
on  the  scleroscope  scale,  the  actual  readings  running  from  92  to  96  for  the 
shell  and  from  89  to  93  for  the  core.  The  specimen  illustrated  was  pre- 
pared from  a  piece  of  98-point  carbon  steel  heated  to  1410°  F.,  quenched 
until  cold  in  water  at  85°  F.,  drawn  in  oil  to  a  temperature  of  440°  F.,  and 
then  ground  away  J  in.  on  one  edge.  This  ground  surface  was  then  pol- 
ished with  several  grits  of  successively  increasing  fineness,  the  last  one  used 
being  Turkish  rouge.  After  the  final  polishing  the  surface  was  etched  for 
about  40  seconds  with  a  7  per  cent  solution  of  iodine.  After  careful  wash- 
ing in  alcohol  it  was  allowed  to  remain  in  the  air  for  a  few  seconds  until 
oxidation  commenced.  It  was  then  at  once  coated  with  white  vaseline  as 
a  preservative.  This  method  of  preparing  and  keeping  the  steel  specimens 
for  microscopic  study  is  one  that  was  regularly  followed  in  these  inves- 
tigations. The  7  per  cent  solution  of  iodine  can  be  bought  at  any  drug- 
store. The  white  vaseline  is  found  a  better  preserva- 
tive than  any  of  the  oils,  for  the  reason  that  it  is  free 
from  acid. 

Fig.  613  illustrates  a  block  of  steel  1  in.  square 
treated  in  the  same  manner  as  the  piece  in"  the  pre- 
ceding  view.  The  difference  in  hardness  of  the  two 
areas  on  the  scleroscope  scale  is  about  3  to  5  points. 

To  show  more  clearly  the  relationship  between  the 


subdivisions  of  the  shell  and  core,  Fig.  614  is  presented.  FIG.  614.  —  Areas  of 
This  diagram  is  typical  of  the  polished  and  etched  different  hardness  in 
surfaces  of  the  specimen  in  Fig.  613.  die  steel 

In  Fig.  614  the  hard  outer  shell  is  indicated  by  the  dark  border  A. 
Directly  inside  this  is  a  white  line  B.  Inside  of  B  is  a  faint  shadowy 
border  C  of  about  the  same  width  as  A.  And  inside  of  border  C  is  the 
soft  center  D. 

In  considering  the  structure  of  a  die  with  an  attempt  to  state  the  re- 
sults that  will  come  from  using  a  die  having  these  various  areas  of  hardness, 
the  following  outline  seems  to  be  true :  The  best  service  will  come  from  the 
hard  border  A  of  Fig.  614.  This,  in  a  properly  hardened  piece,  is  about 
TV  in.  wide  up  to  the  line  B.  Beginning  with  the  line  B  and  running  inward 
toward  the  center  D,  the  structure  is  such  that  grooving  or  rapid  wear 
may  take  place  if  a  part  of  the  die  having  this  structure  is  used  as  a  cutting 
edge.  In  some  unsuccessful  dies  the  white  line  B  has  been  found  as  close 
as  0.010  in.  from  the  cutting  edge  and  it  has  even  run  clear  to  the  edge. 
It  is  evident  that  such  a  die  was  either  improperly  designed  or  improperly 
made  and  hardened  to  give  maximum  results. 

To  further  illustrate  this  point  the  authority  quoted  refers  to  a  die 
shown  in  Fig.  615  which  exhibits  all  the  lines  of  the  specimen  in  Fig. 
613  except  that  the  white  line  corresponding  to  the  border  B  of  the 


422 


PUNCHES  AND   DIES 


diagram,  Fig.  614,  is  broken  and  the  center  color  runs  clear  through  the 
hard  border  to  the  cutting  edge.  When  on  test  in  the  press,  this  die  ran 
only  1  hour  at  a  cutting  speed  of  480  strokes  per  minute  when  it  became  dull 
and  grooved  at  the  points  where  the  center  color  ran  out  to  the  edge. 

T^ie  history  of  this  die  was  investigated  and  it  was  found  to  have  been 
improperly  hardened,  having  been  dipped  with  the  grooved  face  down 

instead  of  vertical  and  moved 
rapidly  with  an  up  and  down 
motion.  This  allowed  steam 
and  vacuum  pockets  to  form 
in  the  groove,  preventing  the 
cooling  water  from  reaching 
the  surface,  creating  the  soft 
spot  that  later  scored  when 
the  die  was  placed  in  service. 
A  duplicate  of  this  die 
made 'from  the  same  steel  at 
the  same  time  and  hardened 
the  same  way  also  ran  only 
1  hour  under  test.  It  was 
then  removed,  annealed,  re- 
faced,  and  properly  hardened. 
The  hardening  this  time  con- 
sisted in  dipping  it  with  the 
grooved  face  vertical  and 
moving  it  in  such  a  way  and 
at  such  a  rate  that  neither 
steam  nor  vacuum  pockets  could  form  in  contact  with  the  surfaces  that 
later  on  were  to  form  cutting  edges.  This  die  was  then  put  to  test  and 
ran  for  11  hours  at  a  speed  of  480  strokes  per  minute.  The  first  die  cut 
only  some  20,000  holes  before  grooving  and  dulling.  The  second  die 
cut  about  220,000  holes  before  dulling.  These  records  show  two  things. 
First,  the  possibility  of  greatly  increasing  the  service  of  dies  if  they  are 
properly  made,  and  second,  the  importance  of  obtaining  the  hard  outer 
shell  of  hardened  high  carbon  tool  steel  on  all  surfaces  that  are  to  furnish 
cutting  edges. 

DIE  HARDNESS  AFFECTED  BY  PROPORTION 

After  the  tests  noted  above,  search  was  made  to  discover  other  con- 
ditions that  might  produce  soft  areas  in  the  surfaces  that  must  supply  the 
cutting  edge.  This  resulted  in  bringing  out  two  factors  that  have  a  de- 
cided influence  upon  the  thickness  and  relationship  of  the  various  hard- 
ness layers  outlined  in  the  diagram,  Fig.  614. 


FIG.  615.  —  Notching  die,  showing  hardness  lines 
on  surface 


SOME  HARDENING  PRINCIPLES  APPLIED  TO   DIES 


423 


One  of  the  troublesome  problems  was  the  hardening  of  small  holes  and 
openings  in  the  dies.  If  dies  are  to  be  made  to -give  maximum  service, 
permitting  them  to  be  worn  down  from  1  in.  thick  at  the  outset  to  J  in.  at 
the  end,  it  is  evident  that  the  inside  of  all  of  the  openings  for  cutting  edges 


Sec-Hon  X-Y 


FIG.  616.  —  Diagrammatic  section  of  a  solid  die,  showing  areas  and  lines  of  hardness 

must  be  uniformly  hard  from  top  to  bottom.  That  this  condition  did  noj 
exist  in  many  dies  as  ordinarily  made  has  been  proved  time 'and  again  j 
Often  a  die  would  start 
by  giving  excellent  pro- 
duction records  for  the 
first  few  grindings;  then 
these  records  would  begin 
to  change,  giving  fewer 
and  fewer  blanks  per  grind- 
ing until  only  one-quarter 
or  even  one-tenth  as  many 
were  being  produced  as  at 
first.  If  the  die  was  kept 
at  work,  these  records 
would  begin  to  improve 
after  having  reached  a  low 
point,  and  perhaps  come 
back  to  an  amount  nearly 
if  not  quite  equal  to  that 
produced  at  first. 

The  conclusion  arrived 
at  as  to  the  cause  for  this 
is  indicated  by  Fig.  616. 


81  -ho  85 
FIG.  617. 


9!&Up 

Difference  in  hardness  over  surface  of  a 
large  hardened  die 


The  outer  surfaces  of  the  die  from  which  the  heat  could  be  easily  abstracted 
in  quenching  possessed  the  proper  thickness  of  hard  shell.  But  as  the  middle 
of  the  original  length  of  the  hole  is  approached  the  heat  could  not  be  abstracted 
rapidly  enough  in  cooling  and  a  place  is  found  where  the  hard  shell  is  compar- 
atively thin  and  cannot  stand  up  to  give  maximum  service.  Actual  differ- 
ences in  hardness  over  the  surface  of  a  die  are  plainly  shown  by  Fig.  617. 


424 


PUNCHES  AND  DIES 


FIG.  618.  —  Die  with  proportion  holes  for 
hardening  properly 


From  this  condition  it  is  concluded  that  there  was  too  much  heat  per 
square  inch  of  surface  area  in  the  hole  to  produce  satisfactory  hardening. 
It  is  probable  that  the  length  of  time  required  for  the  heat  to  flow  out  has 
an  important  effect  upon  the  thickness  and  character  of  the  hard  layers. 
Thus  in  designing  dies  it  is  important  to  proportion  them  so  that  an  ex- 
cessive amount  of  heat  will  not  be 
compelled  to  flow  through  surfaces 
that  later  on  are  to  form  cutting 
edges. 

This  is  called,  by  Mr.  Dean, 
the  principle  of  proportion  in  die 
design.  In  Fig.  618  is  a  die  which, 
as  he  points  out,  has  had  a  number 
of  round  holes  drilled  through  it 
for  the  purpose  of  giving  proper 
proportion.  In  fact  all  the  holes 
except  the  slots  are  for  the  purpose 
of  obtaining  proper  proportion  to 
control  hardening.  These  holes 
are  so  located  as  to  bring  only  a 
comparatively  small  mass  of  solid 
metal  around  each  working  slot  and  so  that  the  heat  from  every  section 
around  a  working  hole  must  be  able  to  flow  in  at  least  two  directions  to 
quenching  surfaces,  provided  one  of  these  surfaces  is  that  of  a  working 
hole  or  opening. 

INFLUENCE  OF  FINISH  ON  DIE  HARDENING 

The  second  factor  which  has  a  very  marked  influence  upon  die  hardening 
and  upon  the  thickness  and  uniformity  of  the  outside  hard  shell  is  the 
surface  finish.  For  a  number  of  years  the  authority  quoted  had  standard- 
ized surface  finishes  that  were  required  for  all  dies.  Because  of  the  de- 
carbonization  and  oxidation  that  take  place  when  heating  a  die,  a  thin, 
almost  imperceptible  coating  of  scale  forms  on  the  surfaces.  The  thickness 
and  nature  of  this  scale  and  the  ease  or  difficulty  with  which  it  is  cast  off 
when  the  steel  is  immersed  in  water  have  a  decided  influence  upon  the  hard- 
ness. The  ideal  condition  is  one  where  the  scale  is  very  thin,  is  uniform  all 
over  the  die,  and  is  cast  off  as  soon  as  the  steel  enters  the  quenching  water. 

It  is  easy  to  make  a  simple  test  showing  this  thin  scale.  Take  a  small 
white  porcelain  dish,  fill  it  with  clear  water,  heat  a  piece  of  steel  and  then 
immerse  it.  The  thin  scale  can  be  seen  to  float  away  from  the  surface  of 
the  steel.  Microphotographs  magnified  to  1200  diameters  show  openings 
or  fissures  through  the  scale,  and  also  a  multitude  of  tiny  cables  holding 
this  scale  to  the  surface  of  the  steel.  The  intervening  space  was  filled  with 


SOME  HARDENING  PRINCIPLES  APPLIED  TO  DIES  425 

steam  when  the  shell  was  hardened,  thus  preventing  the  free  flow  of  heat 
and  interfering  with  the  hardening  process. 

The  most  detrimental  finish  to  successful  hardening  seems  to  be  a  tear- 
ing cut  with  a  fine  feed  and  a  dull  tool,  such  as  can  be  produced  in  the 
lathe,  planer,  or  shaper.  A  certain  specimen  shows  scratches  made  on  two 
faces  of  a  steel  block  1  in.  square.  One  side  was  finished  smooth,  the  other 
so  as  to  produce  steam  pockets.  The  block  was  hardened  at  1410°  F. 
and  0.002  was  ground  off  each  face  after  hardening.  Each  face  was 
then  scratched  by  a  fine  needle  mounted  in  a  steel  ball;  this  needle  was 
merely  drawn  across  the  ground  faces  without  applying  any  pressure  except 
that  of  the  weight  of  the  ball.  The  face  that  was  finished  with  a  surface 
suitable  for  hardening  shows  no  scoring  or  scratching  from  the  needle. 
On  the  other  hand,  the  scratches  on  the  other  surface  are  very  noticeable. 

In  order  to  obtain  satisfactory  commercial  results  in  die  hardening,  the 
finish  on  dies  has  been  standardized  to  one  which  is  equal  to  that  obtained 
from  a  No.  2  Swiss  file  on  a  flat  surface.  There  is  a  difference  of  about  one 
number  between  the  grades  of  the  imported  Swiss  files  and  the  American 
Swiss.  The  No.  1  American  is  nearly  equal  to  the  No.  2  imported.  Each 
leaves  about  the  same  grade  of  finish  on  the  work.  * 

A  flat  file  will  leave  a  smoother  finish  than  a  round  or  half-round  file  of 
the  same  number  and  cut.  If  one  looks  closely  at  a  half-round  file,  he 
will  see  that  it  presents  a  series  of  small  corners  to  the  work  instead  of  a 
smooth  cutting  edge.  To  test  the  various  kinds  of  finish,  take  a  piece  of 
tool  steel  §  in.  thick  and  file  it  with  a  No.  2  Pillar  file  until  the  surface  is 
straight  and  smooth.  Then  take  a  J-in.  No.  2  round  file  and  file  a  half- 
circle  about  J  in.  deep  in  the  steel.  The  edge  where  the  half-round  groove 
meets  the  top  flat  surface  will  look  like  a  saw  when  examined  under  the 
microscope.  The  other  straight  edges  that  have  been  filed  will  show 
smooth  and  even. 

A  No.  4  half-round  file  will  leave  approximately  the  same  finish  on  a 
curved  surface  as  a  No.  2  flat  file  will  leave  on  a  straight  surface.  It  is 
important  to  give  a  half-round  file  a  slight  rotating  motion  during  the 
forward  stroke  of  filing. 

Too  high  a  finish  or  polish  on  a  die  seems  to  have  the  effect  of  repelling 
the  water  when  the  piece  is  immersed  for  hardening.  The  quality  of  the 
finish  should  be  neither  too  coarse  nor  too  fine,  though  at  all  times  a  tool 
maker  should  be  careful  not  to  confuse  smooth  finish  with  flat  finish.  A 
piece  of  steel  with  a  corrugated  surface,  or  one  cut  with  a  coarse  feed,  will 
harden  successfully  if  the  surface  of  the  corrugations  or  feed  marks  is 
smooth;  and,  in  fact,  it  will  present  more  cooling  surface  to  the  water 
than  a  flat  surface.  At  the  same  time,  unless  such  a  piece  is  moved  in  the 
water  in  such  a  way  that  the  liquid  flows  lengthwise  of  the  grooves,  steam 
pockets  are  likely  to  form  and  unequal  cooling  take  place. 


LIST   OF  REFERENCES 

PAGE 

CHAMBOSE,  W.  E ' 183,  184 

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DOESCHER,  CHAS ,.,..*. "  178 

DOLINSKY,  R. .    . ;   ^    ........       58 

DEAN,  EDWARD , 420-425 

GREENLEAF,  W.  B.    .'.  V  .;,   .'  --.' ';  '''. ''.  '.'-.    .   ...  /,..-.' 321 

JONES,  W.  L.      .    .    .    .    . 226 

KAIL,  CHAS.  F. 182 

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KUHNE,  GEO.  F ,   ..'.;,.   .   .    .    .    .    .   /..    .    .    179,180,193,368 

LEACH,  E.  J.  .    .  -...<!..-.  \.   .    .   .    ; •'-'. .';.''• ..^ 185 

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LERCH,  G ^    ..-.     294 

LOVELL,  C.  V 63,  66,  68,  71-73,  346 

LUCAS,  C.  W 190,  191 

MAWSON,  R.  W 171-176 

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MERRIAM,  F.  W .    .    .     253-255 

NUTE,  H '.   .V  .    .    .     408 

PALMER,  S.  W 252 

PUSEP,  H.  F 243,  377-379 

RANDALL,  H.  J \    . 194 

RAUTER,  FRED .../............       90,  223-225 

SCHAUER,  H.  A. ,   .    .   .   .....     388 

STARRER,  C.  W 109 

WALTERS,  ERNEST  A 79,  196-204,  226,  227 

WEBER,  W.  L 358 

WELLS,  W.  J .  /  .   . 373 

WlNKLEMEAN,    W.    C.     .     /    .     /.     .-,     .     .     .     .     ...../• 186 

WRIGHT,  M.  S 348-354 


426 


INDEX 


Adaptor  for  machining  and  grinding  dies, 

382 

Adjustable  square  for  die-makers,  388,  389 
Allowances  for  shaving,  125 
Aluminum,  drawing  dies  for,  207 

drawing  large  work  in,  204 

embossing  dies  for,  309 
Angular  adaptor  for  holding  die  work,  381 
Annealing  and  pickling  brass  shells,  180 
Arch  type  sub  press,  337,  338 
Area  of  circles  and  squares,  finding,  361 
Area  of  circular  ring,  360 
Areas  of  different  hardness  in  die  steel,  421, 

423 

Area  of  shell  blanks,  360-370 
Area  of  sphere,  finding,  360 
Automobile  hubs,  dies  for,  197 

bulging  dies  for,  202 

perforating  dies  for,  203 

trimming  dies  for,  204 

B 

Bench  filing  machine  files,  386,  387 

standard  cuts  for,  388 
Bending  and  forming  dies,  18,  236 

for  ammunition  box  trimmings,  fittings, 
253 

for  coin  chute,  260 

Bending  dies  combined  with  blanking  and 
piercing  tools,  238 

for  double  operation,  240 

for  a  light  bracket,  243 

for  a  round  rod,  237 

for  a  sheet  steel  hinge,  244 

knock  out  for,  243 

plain,  236 

for  coin  register  wheels,  320 

for  margin  strip  for  typewriter,  271 

for  typewriter  spring,  273 
Blanked  parts,  examples  of,  23 


Blanking   and   marking   die,   progressive 

type,  249 
Blanking  and  piercing  dies,  progressive,  70 

for  margin  stop  for  typewriter,  269 
Blanking  and  piercing  punches  held  by 

screw  at  end,  71 
Blanking  die  action,  9 

clearance,  29 

clearances,  table  of,  31 

cutting  edges,  9 
Blanking  dies,  double,  45 

for  calculating  machine  covers,  278 

for  cam  work,  130 

for  cartridge  cases,  177 

for  coin  register  wheels,  320 

for  crescent,  308 

for  fiber,  14 

for  large  oval  parts,  50 

for  motor  parts,  49 

for  rocker  arm,  40 

for  slender  work,  39 

for  thick  cams,  155 

for  thick  stock,  44 

for  thin  stock,  46 

for  typewriter  bar,  264 

for  typewriter  type  bar,  312 

for  wheels,  sub  press,  26 

internal,  50 

inverted,  48 

large,  48 

life  of,  32 

precision  layout  for,  400-403 

with  oblique  opening,  42 

with  pressure  pad  and  stripper,  46 
Blanking   work  at  an  angle  to  edge  of 

stock,  42,  43,  44 
Blanking,  piercing,  and  bending  dies  for  a 

small  bracket,  238 

Blanking,  piercing,  and  forming  tools  for 
typewriter  work,  263 

punch  and  die  open  type,  5 
Blanking    punch    for    starting    a     curl, 
261 


427 


428 


INDEX 


Blanks  for  rectangular  box,  finding  area 
of,  369 

Blanks  for  shells,  finding  size  of,  360,  370 
table  of,  363,  368 

Blocks,  standard  punch  and  die,  342-359 

Bolsters,  locating  holes  in,  356,  358 

Boring  out  large  dies,  395 

Brass  bushing,  compound  die  for  trimming, 

233 
coupling,  compound  tools  for  making, 

227 
shells,  annealing  and  pickling,  180 

Britannia  white  metal,  drawing  inside  out, 

194 
lubricant  for  drawing,  195 

Broaches  for  wheel  shaving  die,  410,  411 

Broaching  a  shaving  die,  411 

Bulging  dies,  17 

for  automobile  hubs,  202 

Bushed  dies,  65 

Bushing,    brass,    combination    and    com- 
pound tools  for,  228 

Button  dies,  table  of,  63 

Button  method  for  locating  holes  in  dies, 
397 

C 

Calculating  machine,  brass  cover,  dies  for 
making,  288,  293 

drawing  dies  for,  291 

forming  dies  for,  292 

piercing  dies  for,  292 

trimming  dies  for,  291 
Calculating     machine     covers,     blanking 
tools  for,  278 

details  of,  278 

dies  for,  276-293 

Calculating  machine  cover  plate,  emboss- 
ing die  for,  286 

forming  die  for,  286 

marking  die  for,  285 

piercing  dies  for,  280,  282 

trimming  dies  for,  287 
Cam  blanking  dies,  154 
Cams,  slotted,  shaving  dies  for,  134 

small,  trimming  dies  for,  143 
Cartridge  case,   1  lb.,  drawing  dies   for, 
172 

indenting  die  for,  172 

operation  on,  174 

18  lb.,  drawing  dies  for,  175 

30  rifle,  drawing  dies  for,  177 


Cartridge  cases  (Howitzer),  drawing  dies 

for,  176 
Cast-iron  dies  for  drawing,  208 

for  large  drawing  operation,  209 
Center  punch,  circle  marking,  378,  379 

spacing,  377,  379 

Circles,  finding  dimensions  of,  361 
Circular  ring,  finding  area,  360 
Classification  of  dies,  2 
Clearance  or  relief  for  blanking  dies,  29 
Clearances  between  punch  and  die,  table 

of,  35 

Clock  frame  dies,  compound  sub  press,  341 
Clock  wheel  die,  sub  press,  339 
Coin  changer  casing,   forming  tools  for, 

302,  303 

Coin  chute,  tools  for  blanking  and  form- 
ing, 260,  261 

Coin  register,  changer  back,  295 
end  forming  tools  for,  297 
finish  forming  tools  for,  299,  301 
piercing  and  trimming  dies  for,  295,  296 
Coin  register  dies,  294 
Coin  register  part,  blanking,  piercing  and 

embossing,  dies  for,  308 
Coin  register  wheels,   blanking,  bending, 

piercing,  dies  for,  320 
riveting  tools  for,  319 
Coining  dies,  21 
Comb  dies,  12 
Combination  blanking  and  drawing  dies, 

for  brass  bushing,  details  of,  230 
for  forming  a  shallow  cover,  215 
for  pawl  housing,  222 
for  taper  shell  work,  217 
pressure  springs  in,  217 
Compound  die,  details  of,  94 
Compound  die  shoes,  standards  for,  355, 

356 

Compound  die  standards,  356,  357 
Compound  dies  compared  with  progressive 

dies,  95 
Compound  dies  for  a  hemispherical  bell, 

219 

for  blanking  and  piercing  a  small  disk,  93 
arrangement  of,  92 
for  clock  wheel,  sub  press,  339 
for  electrical  work,  108 
for  making  lock  washers,  110 
for  stator  punchings,  108 
for    blanking,    drawing,   forming,    and 
piercing,  226 


INDEX 


429 


Compound  dies  for  thin  washers,  97 

for  piercing  and  blanking  a  thin  shim,  95 

for  piercing  and  blanking  small  gears, 
100 

for  trimming  brass  bushings,  231 

for  valve  spring  cap,  225 

for  large  circular  work,  104 

for  large  rectangular  blank,  106 

sub  press,  337 

with  transfer  device,  332 
Cone,  finding  area  of  surface,  360 
Cupping  dies  for  1  Ib.  cartridge  cases,  174 

for  washer  with  key  slots,  102 

for  wire  mesh  disk,  234 
Compound  punch  holders,  356 
Cupping  thick  metal,  178 
Curled  work,  18 
Curling  operation,  261 
Cutting  off  dies  combined  with  slotting 
dies,  115 

for  round  end  work,  114 
Cutting  off  .or  parting  dies,  13 

combined  with  piercing  tools,  112 
Cutting  off  tools  for  German  silver  bars, 
117 


Die  and  punch  standards,  342-359 

Die-hardening,  influence  of  finish  in,  424 

Die  hardness,  effect  of  proportion.,  422 

Die-makers  files,  383-388 

Die  opening,  working  out,  381 

Die  shoes  and  punch  holders  for   1   Ib. 

cartridge  case  work,  172 
Die  shoes,  compound,  standards  for,  355, 

356 

Die  sinkers  files,  385 
Die-makers'  squares,  388,  389 
Die  surface,  finishing,  425 
Die  steel,  areas  of  different  hardness,  421 
Die  steel,  layers  of  different  hardness,  420 
Die  work  in  the  lathe,  large,  393 
Dies,  see  blanking,  bending,  drawing,  etc. 
Dimensions  of  circles  and  squares,  finding, 

361 

Double  blanking  dies,  45 
Dowel    pins    for    shaving    die,    finishing 

417 
Drawing  and  forming  a  brass  cover  for 

calculating  machine,  288 
Drawing   and   forming   dies   for   a  large 

cover,  213 


Drawing  and  trimming  dies  for  taper  shell, 

combination,  218 
Drawing  die,  edges,  167 
Drawing  dies,  allowance  between  punch 
and  die,  167 

their  action  upon  material,  163 

''closed  bottom"  form,  169 

combination,  171 

for  automobile  hubs,  clearance  in,  198 

for  brass  cover  for  calculating  machine, 
290 

for  0.30  cartridge  cases,  177 

for  1  Ib.  cartridge  cases,  172 

for  18  Ib.  cartridge  cases,  175 

for  4.5  Howitzer  cases,  176 

for  conical  shells,  188 

for  large  aluminum  work,  207 

for  making  oil  can  spouts,  190 

for  shells,  171 

for  square  work,  192 

for  square  work,  laying  out  corners,  193 

gang,  for  steel  thimbles,  195 

general  types,  169 

of  cast  iron,  208,  209 

"pinch  off"  principle,  187 

"push  through"  form,  169       « 

radius  of  drawing  edge,  168,  172,    175, 
176,  179 

triple  action,  171 

typical  construction,  168 

working  of  metal  in,  165 
Drawing  edges,  comparison  of,  179 
Drawing  edges  on  drawing  dies,  168,  172, 

175,  176,  179 

Drawing  flanged  shells,  183 
Drawing  large  work  of  aluminum,  204 
Drawing  press,  double  action,  170 
Drawing  press  with  spring  pressure   plate 

under  bed,  212 
Drawing  process,  15 

avoiding  wrinkling  of  work,  167,  192 

displacement  of  material  in,  164 

lines  of  movement  in,  167 

limitations  of  metal  flow,  166 
Drawing  punches,  vent  in,  178 
Drawing  steel  shells,  two  methods,  182,  18$ 
Drawing  tool  action,  16 
Drawing  work  inside  out,  192 
Drifts  for  dies,  380 
Drilling  out  stock  in  die  outline,  378 
Drilling  screw  holes  in  shaving  die  holder,  415 
Drills  for  spotting,  380 


430 


INDEX 


E 

*  Elliptical  die  work,  large,  394 
Elliptical  dies,  51,  52 
Ellipse,  finding  area,  360 
Embossing  dies,  20 
Embossing  dies  for  aluminum  plate,  309 

for  brass  crescent,  307 

for  calculating  machine  cover  plate,  286 

for  corrugated  disk,  308 

for  large  work,  310 

for  typewriter  platen  ratchets,  304 
Extruding  dies,  22 


Finish  in  die  hardening,  influence  of,  424 
Files,  bench  machine,  386,  387 

for  die  work,  383-388 

needle,  384 

Filing  process  on  dies,  383 
Filing  shaving  die  on  bench  machine,  410 
Flanged  shells,  drawing,  184 
Flat  forming  or  curling,  248 
Fluid  dies,  17 
Forming  and  bending  dies,  18 

for  a  steel  clip,  245 

Forming  and  piercing  tools  for  second  oper- 
ation on  coin  changer  back,  298 
Forming  dies  for  finishing  work  after  bend- 
ing, 247 

for  brass  cover  for  calculating  machine, 
292 

for  calculating  machine  cover  plate,  286 

for  coin  changer  casing,  302,  303 

for  coin  register  changer  back,  297,  298 

for  end  of  coin  changer  back,  299 

for  large  cover,  213 

for  small  channel,  258,  259 

for  springs,  252 

for  typewriter  ribbon  cores,  276,  277 

for  universal  bar  for  typewriter,  266,  267 

large,  of  £ast  iron,  210,  211 


Gages  for  sheet  stock,  corresponding  thick- 
nesses, 35 
Gang  dies,  45 

Gang  drawing  dies  for  steel  thimbles,  195 
Gang  piercing  dies,  65 
Gear  wheel,  shaving  dies,  122 


Gear  wheels,  compound  dies  for,  100 
Graduating  dies  for  straight  bar,  331 
Grinding  dowel  pins  for  shaving  dies,  417, 

418 

Grinding  shaving  punch  shank,  415 
Grinding  out  dies,  389 
Guide  pins  and  bushings,  347,  353,  354 


Hardened    die    steel,    layers    of    different 

hardness,  420 
Hardening  principles  applied  to  dies,  420- 

425 
Hardness  lines  on  notching  die,  422 


Indenting  dies  for  1  Ib.  cartridge  cases,  172 
Indicator  for  setting  punch  in  bench  lathe. 

414 

Indicator  used  in  the  lathe,  397 
Indicator  used  on  dies  before  grinding,  391 
Internal  blanking  tools,  49,  50 
Indexing  and  transfer  dies,  324 
Indexing  dies  for  notched  disks,  324 
Indexing   die   for   notching   a   typewriter 

comb,  327-330 
Indexing  perforating  die,  325 
Inverted  blanking  dies,  48 


Jewelry  dies,  "pinch  off,"  186 

K 

Knock  out  bushing  for  compound  die,  110 
Knock  out,  positive,  application  of,  99 


Lathe  work  on  punches,  392 

Laying  out  dies  with  vernier  height  gage, 

376 

Laying  out  templets  and  dies,  371-395 
Locating  and  boring  holes  in  dies,  372 
Locating  blanks  in  stock,  39 
Locating  holes  in  dies,  396-407 

button  method,  397 

with  vernier  height  gage,  398 
Lapping  a  shaving  die,  412 
Locating  limit  holes  in,  397 


INDEX 


431 


M 


Machine  files,  386,  387 
Machine  filing  of  dies,  386 
Margin  stop  for  typewriter,  268 

dies  for  piercing  and  blanking,  268,  269 
Marking  dies  for  calculating  machine  cover 

plates,  285 
Master  plates,  403 

examples  of,  406 

uses  of,  405 

Milling  punch  for  shaving  die,  413 
Motor  disk  piercing  dies,  66 
Mounting  punches  in  plates,  358,  359 
Muffler  cup  tools,  225 
Multiple  piercing  dies,  64 


N 

Needle  files,  die-makers,  384 
Notching  dies,  12 

for  typewriter  comb,  327-330 
Notching  electrical  parts,  methods  of,  108 

hardness  lines  on  surface,  422 
Nest  on  trimming  dies  for  small  rocker 

arms,  150 
Nest,  shaving  die,  for  cam  slots,  136 

for  heavy  stock,  138 

for  small  lever,  137 

for  wheel  shaving  die,  making,  416 


O 

Oblique  hole  piercing  tools,  90 

Oil  can  spout,  sequence  in  making,  190 

Open  blanking  dies,  24,  25 

Opening  in  die,  position  of,  38 

Oval  blanking  dies,  50,  51 

Overhang  type  sub  press,  334 


Parting  tools,  see  cutting  off  dies,  117 
Perforating  dies,  indexing,  325 

for  automobile  hubs,  203 

for  large  number  of  holes,  63 
Pickling    and    annealing    brass    shells   for 

drawing,  180 

Pickling  shells,  effect  of  acid,  181 
Piercing  and  blanking  dies  for  margin  stop 

for  typewriter,  269 


Piercing  and  blanking  punches  held  by 

screw  at  end,  71 

Piercing  and  cutting  off  dies,  113 
Piercing  and  trimming  dies  for  small  rocker 
arm,  149 

for  coin  changer  back,  295,  296 
Piercing,     blanking     and     countersinking 

washers,  79 
Piercing,  blanking  and  forming  dies  for  a 

lever  tower  cap,  223 
Piercing  dies  bushed,  65 

double,  59 

for  brass  cover,  292 

for  calculating  machine  cover  plate,  280, 
282 

for  coin  register  wheels,  320 

for  curved  slot,  11 

for  links,  60 

for  motor  disks,  66 

for  oblique  holes,  90 

for  series  of  slots,  details  of,  86 

for  several  holes  in  a  straight  line  ,67 

for  slots,  78 

for  thick  blank,  double,  69 

for  typewriter  type,  317 

for  typewriter  type  bar,  315 

for  universal  bar  for  typewriter,  265 

gang,  65 

internal  clearance  in,  64 

multiple,  64 

plain  and  spiral  types,  11 

simple  form,  10,  61 

side  operated,  88 
Piercing,    forming    and    cutting    off    dies, 

118 

Piercing,  pressure  required,  61 
Piercing  punch  pad  for  compound  die,  356, 

357 
Piercing  punches  held  by  set  screws,  table 

of,  68 

Piercing  punches,  table  of,  66 
Piercing  tools,  57 

for  a  sheared  plate,  multiple,  80 
Pillar  sub  press,  335 
Pillar  sub  press  dies,  bases,  heads  and  pins 

for,  28 

Pillar  dies,  standard  blocks  for,  343,  344 
Pilots  for  punches,  table  of,  71 
"Pinch  off  "dies,  186 
Precision  drilling  machine,  400-402 

layouts  for,  400 
Precision  layout,  399 


432 


INDEX 


Press,  double  action,  170 

operation,  with  two  machines,  198 

toggle,  drawing  aluminum  in,  205,  206 
Pressure  pad,  blanking  die,  46 
Pressure  pads  and  nests,   dimensions  of, 

344 

Pressure  plate  attached  to  press,  212 
Pressures  required  for  piercing  metal,  62 

for  shearing  metals,  37 
Position   of  blank   in   stock,   various  ex- 
amples, 44 

Position  of  opening  in  die,  38 
Progressive  blanking  punches  with  pilots,  72 
Progressive  dies,  arrangement  of,  7 

compared  with  compound  tools,  95 

for  automobile  hubs,  197 

for  blanking  and  piercing  washers,  70 

for   blanking   and   piercing   rectangular 
parts,  73,  74 

for    blanking    and    piercing    typewriter 
parts,  77 

for  interrupted  gear  wheel,  75 

for  piercing,  forming  and  cutting  off,  119 

for  three  operations,  79 

sub  press  advantages,  336 
Proportion   holes   for   die   hardening,    424 
Punch  and  die  standards,  342-359 
Punch  dies,  57 

shear  on  spiral  end,  58 

clearance  for,  58 

for  plate  work,  58 
Punch  pilots,  71,  72 
Punch  work  in  the  lathe,  392 
Punches    for    rivets,    allowances    between 
punch  and  rivet  size,  59 


11 


Riveting  dies,  21 

Riveting  and  staking  tools  for  coin  register 

wheels,  319,  321 
Reamers  for  die  holes,  418,  419 
Rectangular  box,  finding  blank  for,  369 
Reducing  dies,  16 
Relief  in  dies,  methods  of  obtaining,  33 


S 


Scrap  chopper,  standard,  345 
Scriber  for  templet  work,  375 
Sectional  blanking  tools  for  a  coin  chute, 
259,  260 


Sectional  die  construction,  8,  54 

die  for  a  series  of  slots,  "81 

dies  made  in  halves,  52 

piercing    dies    for    calculating    machine 

cam  plates,  282,  283 
Sector  of  circle,  finding  area,  360 
Segment  of  circle,  finding  area,  360 
Shaving  and  trimming  dies,  141 
Shaving  dies,  allowances  for  shaving,  125 

advantages  of,  30,  121 

applications  of,  121 

combined  with  trimming  dies  for  small 
lever,  147 

comparative     advantages     of     different 
types,  129 

for  blanks  with  pierced  slots,  130 

for  different  parts,  130-132 

for  gear  blank,  inverted  type,  128 

for  gears,  details  of,  124 

for  heavy  stock,  138 

for  slotted  cams,  adjustable  nest  for,  136 

for  slotted  cams,  how  built  up,  135,  136 

for  slots  of  variable  position,  134,  135 

for  small  cams,  145 

for  small  gears,  122,  123 

for  small  gear  wheels,  408,  409 

for  small  lever,  137 

for  small  wheel,  making  dowel  pins,  417 

for  small  wheel,  making  nest,  416 

for  small  wheels,  reamers  for,  418,  419 

for  steel  cams,  156-158 

for  a  toothed  blank,  13 

for  a  toothed  cam,  130 

for  wheel,  broaches  for,  410,  411 

inverted  type,  how  applied,  129 

making  a  set  of,  408-419 

nests  for,  125 

table  of  allowances,  139,  140 

uses  of,  12 

uses  on  heavy  stock,  121 

w-th  open  nest  for  small  lever,  137 

with  pilot  for  notched  blank,  127 
Shear  on  progressive  dies,  76,  77 
Sheared  tools,  effect  of,  38 
Shearing  metals  in  dies,  pressure  required, 

37 

Shell  blank  sizes,  table  of  363-368 
Shell  blanks,  finding  size  of,  360-370 
Shell  drawing,  annealing  and  pickling  for, 

-180 
Shell  drawing  dies,  4.5  Howitzer,  176 

.30  caliber,  177 


INDEX 


433 


Shell  drawing  dies,  1  lb.,  172 

18  lb.,  175 

Shell  work,  taper,  combination  dies  for,  217 
Shells,  cast-iron  drawing  dies  for,  208 

conical,  drawings  dies  for,  188 

steel,  sequence  of  drawing  operations  in 

cast  iron  dies,  209     •  * 
Side  closing  dies  for  forming  coin  changer 

casing,  303 

Side  piercing  tools,  88 
Slitting  die  for  small  channel,  256,  257 
Slot  piercing  dies,  sectional,  81-85 
Slot  piercing  dies,  various  forms  of  con- 
struction, 87 

Slotting  and  cutting  off  dies,  115 
Spacing  center  punch,  377,  379 
Sphere,  finding  area  of  surface,  360 
Spotting  drills,  380 

Spout  for  oil  can,  sequence  in  making,  190 
Spring  forming  die,  252 

for  typewriter,  bending  tools  for,  273,  275 

pad  in  bending  die,  237 
Square  drawing  dies,  difficulties  with,  192 

laying  out  corners,  193 

radius  of,  192 

Squares  for  die  washers,  388,  389 
Staking  dies,  21 

Staking  tools  for  coin  register  wheels,  319 
Stamping   and  blanking   die,    progressive 

type,  249 
Stamping   die   for   working   numerals   on 

plates,  311 

Standard  guide  pins  and  bushings,  347,  353, 
354 

punch  and  die  blocks,  342-359 

pillar  die  blocks,  343,  344 
Stator  punching  die,  109 
Stator  punchings,  limits  in,  109,  110 
Steel  shells,  drawing,  182 

thimbles,  gang  dies  for  drawing,  195 
Stock  thicknesses,  by  gage  numbers,  35 
Stops  for  stock,  25 

Stripper  and  knock  out  arrangement,  105 
Stripper,  blanking  die,  46,  47 
Sub  press,  alinement  of,  335,  336 

and  its  dies,  334 

arch  type,  337,  338 

barrel  and  base  arrangement,  336 

construction  of,  336 

details  of  parts,  339 

fitting  up,  336 

general  advantages,  334 


Sub  press,  overhang  type,  334 

pillar  type,  335 

wheel  blanking  die,  26 
Sub  press  dies,  336 

advantages  of,  7 

clock  wheel,  339 

Supports  for  bending  die  operation,  246 
Swaging  dies,  19 

for  air  rifle  part,  321,  322 

for  brass  tube,  322 


Tandem  die  work,  sub  press,  337 
Templets  and  dies,  laying  out  and  making, 

371-395 

Templet  tools,  375 
Templets,  layout  for  simple  type,  374 

simple  set,  373 

Thimbles,  steel,  dies  for  drawing,  195 
Transfer  and  indexing  dies,  324 
Transfer  device  for  compound  dies,  332 
Triangle,  finding  area  of,  360 
Traverse  spindle  grinder  on  die  work,  390 
Trimming  dies,  14 

for  automobile  hub,  204 

for  cover  for  calculating  machine,  291 

for  calculating  machine  cover  plate,  287 

for  curved  typewriter  bar,  151 

for  large  cover,  213 

Trimming  and  piercing  dies  for  coin  changer 
back,  295,  296 

for  small  rocker  arms,  149 
Trimming  and  shaving  dies,  141 

for  cams,  144 

for  small  keys,  159 

for  small  lever,  147 

progressive  type;  159 

use  of  air  nozzle  on,  159 
Trimming  dies,  adjustable  for  cam  finish- 
ing, 154 

for  oil  can  spout,  190 

for  series  of  cams,  154 

for  small  cams,  143 

for  straight  work,  142 
Typewriter  comb,  indexing  die  for  notching, 

327-330 

Typewriter  platen  ratchets,   coppering  to 
localize  hardening,  304,  305 

press  tools  for,  304 

Typewriting  setting  dial,  stamping  tools  for, 
305 


434 


INDEX 


Typewriter  type,  piercing  dies  for,  317 
Typewriter  type  bar,  blanking  die  for,  312 

grinding  to  size,  314 

preparing  for  riveting,  313 
Typewriter  work,  blanking  and  other  dies 

for,  264 

Tubes,  drawing  inside  out,  194 
Tube  trimming  dies,  153 


Valve  spring  cap,  compound  tools  for  mak- 
ing, 225 

Venting  drawing  punches,  178 
Vernier  height  gage  for  laying  out  dies,  376 


w 

Wiring  dies,  19 

Wheel  die  and  punch,  milling,  413 

Wheel  die,  compound,  sub  press,  339 

details,  27,  28,  29 
Wheel    shaving ,  die,    broaches    for,    410, 

411 

lapping  out,  412 
making  nest  for,  416 
Washer  with  key  slot,  compound  die  for, 

102 

Wire    screen    disk,    compound    dies    for, 
234 


THIS  BOOK  IS  DUE  ON  THE  LAST  DATE 
STAMPED  BELOW 

AN  INITIAL  FINE  OF  25  CENTS 

WILL  BE  ASSESSED  FOR  FAILURE  TO  RETURN 
THIS  BOOK  ON  THE  DATE  DUE.  THE  PENALTY 
WILL  INCREASE  TO  SO  CENTS  ON  THE  FOURTH 
DAY  AND  TO  $I.OO  ON  THE  SEVENTH  DAY 
OVERDUE. 


ENGINEER 


NG  LIBRARY 


APR  7     1947 


APR  2  7  1948 


MftY  2 


JUN 


1948 


JUL 

JUL  3  1  1343 


DEC  *<  1040 


1 9 


JAN  18  195 
WAY  3  1  195Q     ,  / 


10m-7,'44(1064s) 


392628 


- 

^glfcWjfc 

Library 
UNIVERSITY  OF  CALIFORNIA  LIBRARY 


